Neural metabolic activity in idiopathic tinnitus patients after repetitive transcranial magnetic stimulation

BACKGROUND The central mechanism of idiopathic tinnitus is related to hyperactivity of cortical and subcortical auditory and non-auditory areas. Repetitive transcranial magnetic stimulation (rTMS) is a well-tolerated, non-invasive potential treatment option for tinnitus. AIM To investigate the changes of neural metabolic activity after rTMS in chronic idiopathic tinnitus (IT) patients. METHODS Eleven patients underwent rTMS (1 Hz, 90% motor threshold, 1000 stimuli/day for consecutive 10 d) on the left temporoparietal region cortex. Tinnitus handicap inventory (THI) and visual analogue score (VAS) were assessed at baseline and posttreatment. All patients underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography to evaluate the neural metabolic activity. Data were preprocessed using statistical parametric mapping and Gretna software to extract the regions of interest (ROIs). The correlation between brain areas involved and THI scores was analyzed. RESULTS Baseline and posttreatment parameters showed no significant difference regarding THI score (t = 1.019, P = 0.342 > 0.05) and VAS (t = 0.00, P = 1.0 > 0.05). Regions with the highest FDG uptake were the right inferior temporal gyrus (ITG), right parahippocampa gyrus (PHG), right hippocampus, rectus gyrus, left middle frontal gyrus, and right inferior frontal gyrus in IT patients. After rTMS treatment, IT patients showed increased activities in the right PHG, right superior temporal gyrus, right superior frontal gyrus, anterior insula, left inferior parietal lobule, and left precentral gyrus, and decreased activities in the left postcentral gyrus and left ITG. The ROIs in the right parahippocampa gyrus and right superior frontal gyrus were positively correlated with THI scores (r = 0.737, P = 0.037 < 0.05;r = 0.735, P = 0.038 < 0.05). CONCLUSION Our study showed that 1-Hz rTMS directed to the left temporo-parietal junction resulted no statistically significant symptom alleviation. After treatment, brain areas of the limbic and prefrontal system showed high neutral metabolic activity. The auditory and non-auditory systems together will be the target for rTMS treatment.

New common bile duct morphological subtypes:Risk predictors of common bile duct stone recurrence

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is the primary treatment for removing common bile duct(CBD)stones.The risk factors for CBD stone recurrence after ERCP have been discussed for many years.However,the influence of CBD morphology has never been noticed.AIM To evaluate CBD morphology and other predictors affecting CBD stone recurrence in average patients.METHODS A retrospective analysis of 502 CBD stone patients who underwent successful therapeutic ERCP for stone extraction at our centre from February 2020 to January 2021 was conducted.CBD morphology and other predictors affecting CBD stone recurrence were examined by univariate analysis and multivariate logistic regression analysis.RESULTS CBD morphology(P<0.01),CBD diameter≥1.5 cm[odds ratio(OR)=2.20,95%CI:1.08-4.46,P=0.03],and endoscopic biliary sphincterotomy with balloon dilation(ESBD)(OR=0.35,95%CI:0.17-0.75,P<0.01)are three independent risk factors for CBD stone recurrence.Furthermore,the recurrence rate of patients with the S type was 6.61-fold that of patients with the straight type(OR=6.61,95%CI:2.61-16.77,P<0.01).The recurrence rate of patients with the polyline type was 2.45-fold that of patients with the straight type(OR=2.45,95%CI:1.14-5.26,P=0.02).The recurrence rate of S type patients was 2.70-fold that of patients with the polyline type(OR=2.70,95%CI:1.08-6.73,P=0.03).Compared with no-ESBD,ESBD could decrease the risk of recurrence.CONCLUSION CBD diameter≥1.5 cm and CBD morphology,especially S type and polyline type,were associated with increased recurrence of CBD stones.In addition,ESBD was related to decreased recurrence.Patients with these risk factors should undergo periodic surveillance and standard prophylactic therapy.

Common bile duct morphology is associated with recurrence of common bile duct stones in Billroth II anatomy patients

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is the primary choice for removing common bile duct(CBD)stones in Billroth II anatomy patients.The recurrence of CBD stones is still a challenging problem.AIM To evaluate CBD morphology and other predictors affecting CBD stone recurrence.METHODS A retrospective case-control analysis was performed on 138 CBD stones patients with a history of Billroth II gastrectomy,who underwent therapeutic ERCP for stone extraction at our center from January 2011 to October 2020.CBD morphology and other predictors affecting CBD stone recurrence were examined by univariate analysis and multivariate logistic regression analysis.RESULTS CBD morphology(P<0.01)and CBD diameter≥1.5 cm(odds ratio[OR]=6.15,95%confidence interval[CI]:1.87-20.24,P<0.01)were the two independent risk factors.In multivariate analysis,the recurrence rate of patients with S type was 16.79 times that of patients with straight type(OR=16.79,95%CI:4.26-66.09,P<0.01),the recurrence rate of patients with polyline type was 4.97 times that of patients with straight type(OR=4.97,95%CI:1.42-17.38,P=0.01),and the recurrence rate of S type patients was 3.38 times that of patients with polyline type(OR=3.38,95%CI:1.07-10.72,P=0.04).CONCLUSION CBD morphology,especially S type and polyline type,is associated with increased recurrence of CBD stones in Billroth II anatomy patients.

Healing Behavior of Micropores in Powder Metallurgy 316L Stainless Steel during Hot Forging and Heat Treatment

The healing behavior of micropores in powder metallurgy （P/M） 316L stainless steel during hot forging and subsequent heat treatment was studied. The results showed that hot forging can improve the homogeneity of the pore size and enhance the relative density of material in varying degree due to different forging temperatures. As a re- sult of deformation and diffusion bonding at high temperature, the irregular pores were spheroidized and finally turned into stable inner grain pores. The comparison of compression behavior between P/M and wrought dense mate rials has shown that the pores can either be the obstacles of dislocation movement or be the nucleation sites accelera- ting the reerystallization according to the difference of deformation temperatures.

Particle Shape Dependence of Rheological Behavior for Colloid-polymer Mixtures

The effect of particle shape on the rheological behavior of small particle-large polymer chain mixture solutions has been investigated with two model colloidal silica dispersions, one of which is ellipsoidal（BINDZIL20/440） and the other is spherical（TM40）. It was found that BINDZIL20/440 series showed shear-thickening at lower shear rates and had a lower upper limit in PEO concentration to demonstrate shear-thickening phenomena. The particle shape was identified as the major factor accounting for these differences. This work enables one to control the rheological behavior of colloid-polymer mixture through simply changing particle geometry instead of performing surface modifications, which could be especially useful in cases where only certain chemicals are allowed, for example in vivo applications.