Theta and Alpha Oscillations during the Retention Period of Working Memory by rTMS Stimulating the Parietal Lobe.

Studies on repetitive transcranial magnetic stimulation (rTMS) have shown that stimulating the parietal lobe, which plays a role in memory storage, can enhance performance during the "retention" process of working memory (WM). However, the mechanism of rTMS effect during this phase is still unclear. In this study, we stimulated the superior parietal lobe (SPL) using 5-Hz rTMS in 26 participants and recorded electroencephalography (EEG) while they performed a delayed-recognition WM task. The analyses included the comparisons of event-related spectral perturbation (ERSP) value variations in theta (4-7 Hz) and alpha (8-14 Hz) band frequencies between conditions (rTMS vs. sham), as well as the correlations between different brain areas. Following rTMS, the ERSP values of theta-band oscillations were significantly increased in the parietal and occipital-parietal brain areas (P < 0.05*), whereas the ERSP values of alpha-band oscillations were significantly decreased in the parietal area (P < 0.05*). The ERSP value variations of theta-band oscillations between the two conditions in the left parietal and left prefrontal areas were positively correlated with the response time (RT) variations (by using rTMS, the more subject RT decreased, the more ERSP value of theta oscillation increased). The ERSP value variations of alpha-band oscillations in the left parietal and bilateral prefrontal areas were negatively correlated with RT variations (by using rTMS, the more RT of the subject decreased, the more ERSP value of alpha oscillation decreased). Inter-sites phase synchronization of theta-band EEG between the left parietal and left prefrontal areas, as well as alpha-band EEG between the left parietal and bilateral prefrontal areas were enhanced by rTMS. These results indicated that activities of both parietal and prefrontal areas were required for information storage, and these activities were related to the behavioral responses. Moreover, the connectivity between these two regions was intensified following rTMS. Thus, rTMS may affect the frontal area indirectly via the frontal parietal pathway.

Efficacy of radiotherapy for the treatment of cystic echinococcosis in naturally infected sheep.

BACKGROUND: Radiotherapy is commonly used to treat cancers. To date, there has been no study focusing on the effects of radiotherapy on hydatid disease in large animals. In this study, we aim to investigate the efficiency and safety of radiotherapy for treating hydatid disease caused by Echinococcus granulosus in naturally infected sheep. METHODS: Ultrasound was used to screen naturally infected sheep in an echinococcosis endemic area in Xinjiang, China. A computer tomography (CT) scan confirmed the presence of hydatid cysts. Twenty sheep naturally infected with E. granulosus in the liver and/or lungs were randomly assigned into four groups receiving no irradiation, or X-ray irradiation of low (30 Gy), medium (45 Gy), and high dose (60 Gy), respectively. After three months of radiotherapy, a CT scan was performed to measure the changes in the cysts. The hepatic parasite cysts and host tissues were collected for histology and gene expression analysis. RESULTS: In the animals subject to irradiation, no significant differences were observed in their appetite, daily activities, and weight before and after radiotherapy. Severe calcification was noticed in the cysts subject to a high dose of radiation compared with the groups subject to low and medium doses. Hematoxylin and eosin staining showed that irradiation contributed to the damage of the cyst structure and nucleus in the germinal layers. Quantitative PCR demonstrated that expression of TPX and HSP70 significantly decreased in a dose-dependent manner (P < 0.05). The expression of the EPC1 decreased in the medium- and high-dose groups compared with the low-dose group (P < 0.05). Meanwhile, the expression of radiation-related apoptosis genes caspase-3 and Gadd45 decreased with an increase in the irradiation dose. CONCLUSIONS: Radiotherapy is an option with satisfactory efficiency and safety for treating cystic echinococcosis in sheep with partial response or stable disease at month 3. In future, inhibition of cystic activity using radiotherapy may serve as a new regimen for treating hydatid disease.

Curative effect of radiotherapy at various doses on subcutaneous alveolar echinococcosis in rats.

BACKGROUND: Alveolar echinococcosis (AE) is a disease in human and animals, and the cure rate is unsatisfactory. This study aimed to investigate the curative efficacy of different doses of locally applied radiotherapy on alveolar echinococcosis in rats. METHODS: Rats infected with Echinococcus multilocularis were randomly divided into 4 groups of 15 rats each: low-, middle-, and high-irradiation groups and a control group. Rats in the control group underwent no treatment, while rats in the irradiation groups received 6-MeV radiotherapy at 20 Gy/8 f, 40 Gy/8 f, and 60 Gy/8 f respectively, once every 3 days for a total of 8 times. One month after radiotherapy, wet weight and AE vesicle inhibitory rate were detected in rats of each group. Histopathologic and ultrastructural observations of tissues with AE lesions were performed. RESULTS: In the treatment groups, an obvious inhibitory effect was found in AE rats; the inhibitory rates were 50%, 72%, and 82%, respectively. There were also statistical differences in pathological changes and average wet weight of the lesions compared with the control group (P < 0.05). In the treatment groups, injuries of various degrees were found in the ultrastructure of the laminated and germinal layers in the capsular wall of AE, and injury was most severe in the high-dose group. CONCLUSION: Radiotherapy has a dose-dependent inhibitory effect on the growth of AE.

[X-ray irradiation against Echinococcus multilocularis protoscoleces in vitro].

OBJECTIVE: To explore the effect of X-ray irradiation on Echinococcus multilocularis protoscoleces in vitro. METHODS: Echinococcus multilocularis protoscoleces were collected from cysts of infected Meriones meridianus and then cultured in RPMI 1640 medium. Protoscoleces were subpackaged into culture flasks at a density of about 10(4) per flask after culture for 3 days. Each group has 10 culture flasks. There were seven groups named as blank control group, low dose group (15 Gy and 30 Gy), medium dose group (45 Gy and 60 Gy), high dose group (75 Gy and 90 Gy), albendazole group (2 500 ng/ml), 45 Gy X-ray + 2 500 ng/ml albendazole group, and 75 Gy X-ray + 2 500 ng/ml albendazole group. Protoscoleces received three radiations on every other day with a source-skin distance of 100 cm and at a dose rate of 200 cGy/min after 3 days in culture. At each day after irradiation, protoscoleces were counted by light microscope with 0.1% eosin staining, and calculated mortality rate (per 100 protoscoleces) until all the parasites in experimental groups died. At the same time, the morphological changes of protoscoleces were observed. RESULTS: There were significant differences in protoscolex mortality between X-ray groups and blank control group (P < 0.05), between X-ray + albendazole groups and albendazole group (P < 0.05). Protoscolex mortality in albendazole group were higher than that of blank control group (P < 0.05). Significant difference were also found in protoscolex mortality between albendazole combined with radiation and radiation only (P < 0.05). Before radiation, protoscoleces was normal with complete structure. After radiation, the parasites were mostly valgus type protoscoleces with disordered rostellar hooks and deformed acetabulum, and finally died. CONCLUSION: X-ray can kill Echinococcus multilocularis protoscoleces in vitro.

[Effect of 6 MeV radiotherapy on secondary Echinococcus multilocularis infection in rats].

OBJECTIVE: To explore the effect of 6-MeV X-ray radiotherapy on secondary Echinococcus multilocularis infection in rats. METHODS: Female SD rats were used to develop a secondary infection model, and then randomly divided into experimental group and control group (5/group). Rats in experimental group received two irradiations at 7-day intervals with the same dose (20 Gy) which applied with 6-MeV ray. The rats in control group did not receive any treatment. At one month after the second irradiation, the pathomorphological changes of E. multilocularis cysts were observed. RESULTS: Cysts in experimental group showed different degrees of damage, including that the laminated layer and germinal layer became swollen and separated from each other, brood capsules and protoscoleces were rare. The structure of cysts was normal in control group, laminated layer and germinal layer were clear, and there were many protoscoleces in the brood capsule. CONCLUSION: 6 MeV radiotherapy can inhibit the growth of E. multilocularis.

A novel technique for phase synchrony measurement from the complex motor imaginary potential of combined body and limb action.

In this study, we proposed and evaluated the use of the empirical mode decomposition (EMD) technique combined with phase synchronization analysis to investigate the human brain synchrony of the supplementary motor area (SMA) and primary motor area (M1) during complex motor imagination of combined body and limb action. We separated the EEG data of the SMA and M1 into intrinsic mode functions (IMFs) using the EMD method and determined the characteristic IMFs by power spectral density (PSD) analysis. Thereafter, the instantaneous phases of the characteristic IMFs were obtained by the Hilbert transformation, and the single-trial phase-locking value (PLV) features for brain synchrony measurement between the SMA and M1 were investigated separately. The classification performance suggests that the proposed approach is effective for phase synchronization analysis and is promising for the application of a brain-computer interface in motor nerve reconstruction of the lower limbs.