209 research outputs found

    Evaluating the Influence of Spatial Resampling for Motion Correction in Resting-State Functional MRI

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    Head motion is one of major concerns in current resting-state functional MRI studies. Image realignment including motion estimation and spatial resampling is often applied to achieve rigid-body motion correction. While the accurate estimation of motion parameters has been addressed in most studies, spatial resampling could also produce spurious variance, and lead to unexpected errors on the amplitude of BOLD signal. In this study, two simulation experiments were designed to characterize these variance related with spatial resampling. The fluctuation amplitude of spurious variance was first investigated using a set of simulated images with estimated motion parameters from a real dataset, and regions more likely to be affected by spatial resampling were found around the peripheral regions of the cortex. The other simulation was designed with three typical types of motion parameters to represent different extents of motion. It was found that areas with significant correlation between spurious variance and head motion scattered all over the brain and varied greatly from one motion type to another. In the last part of this study, four popular motion regression approaches were applied respectively and their performance in reducing spurious variance was compared. Among them, Friston 24 and Voxel-specific 12 model (Friston et al., 1996), were found to have the best outcomes. By separating related effects during fMRI analysis, this study provides a better understanding of the characteristics of spatial resampling and the interpretation of motion-BOLD relationship

    Experimental study of chemotherapy related leukocytopenia treated by various peroal leucocyte increasing drugs

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    Background: Clinically, the patients with significant WBC decrease are mostly administered G-CSF, this kind of drugs is expensive and adverse reactions are often seen. In contrast, oral leucocyte increasing drug has small adverse reactions, can be used for longer time and can improve the continuity and stability of treatment. The experimental study based on study of mouse was to evaluate the effects of treatment and chemotherapy of related leukocytopenia by five kinds of commonly used peroal leucocyte increasing drugs.Materials and Methods: We prepared mice chemotherapy related leukocytopenia model by cyclophosphamide intraperitoneal injection, the positive control drug is G-CSF, respectively fill five kinds of peroal Leucocyte increasing drugs (Qijiao Shengbai Capsule, Weixuening Granule, Compound Zaofan Pill, Berbamine and Leucogen Tablets) in the stomach, the experimental group was divided into normal control group (group A), model group (group B), positive control group (Group rhG-CSF, group C) and treatment groups (group D-H), and treatment groups were divided into Qijiao Shengbai Capsule group (group D), Weixuening Granule group (group E), Compound Zaofan Pill group (group F), Berbamine Tablet group (group G) and Leucogen Tablet group (group H). Calculate the death rate, blood routine and important visceral organ index in each group..Results: The death rate of mice in each group has no significant difference (P>0.05). WBC of B, D, E and F groups was significantly lower than that of group A (P<0.05 or P<0.01). WBC of C, G and H groups was significantly higher than those of group B (P<0.01). WBC of D, E and F groups was significantly lower than that of group C (P<0.01). WBC of G and H groups was significantly higher than that of D and F groups (P<0.01), WBC of group H is significantly higher than that of group E (P<0.05). RBC of group F, G and H groups was significantly higher than that of group D (P<0.05 or P<0.01). HB of group H is significantly higher than that of group A (P<0.01). HB of C, G and H groups was significantly higher than that of group B (P average <0.01). HB of D, E and F groups was significantly lower than that of group C (P<0.05 or P<0.01). HB of G and H groups was significantly higher than that of D, E and F groups (P average <0.01). PLT of group H was significantly higher than that of group B (P average <0.05). PLT of F, G and H groups was significantly higher than that of group D (P<0.01). Lung index of group G was significantly higher than that of D, E, F and H groups (P<0.01). Liver index of group H is significantly higher than that of group D (P<0.05). Thymus index of G and H groups is significantly higher than that of group F (P<0.05 or P<0.01).Conclusions: Among all drugs of rising WBC, G-CSF owns strongest effect. In oral drug groups, WBC rising effect of Leucogen Tablets is best, RBC, HB and PLT improvement effect of Berbamine and Leucogen Tablets is best. In addition, Berbamine and Leucogen Tablets respectively caused significant increase of lung and liver index, what indicates that, the two drugs may be accompanied by relevant viscera damage. At the same time, the two drugs also  increased thymus index, which indirectly indicates that, the immunity and regulation abilities of Berbamine and Leucogen Tablets are stronger. The spleen index of Qijiao Shengbai Capsule group was significantly higher than that of Berbamine Tablet and Leucogen Tablet groups, what indicates that, the immunity and regulation abilities of Qijiao Shengbai Capsule may be stronger in oral drug group.Keywords: leucocyte increasing drugs; chemotherapy; leukocytopenia; mous

    EXPERIMENTAL STUDY OF CHEMOTHERAPY RELATED LEUKOCYTOPENIA TREATED BY VARIOUS PEROAL LEUCOCYTE INCREASING DRUGS

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    Background: Clinically, the patients with significant WBC decrease are mostly administered G-CSF, this kind of drugs is expensive and adverse reactions are often seen. In contrast, oral leucocyte increasing drug has small adverse reactions, can be used for longer time and can improve the continuity and stability of treatment. The experimental study based on study of mouse was to evaluate the effects of treatment and chemotherapy of related leukocytopenia by five kinds of commonly used peroal leucocyte increasing drugs. Materials and Methods: We prepared mice chemotherapy related leukocytopenia model by cyclophosphamide intraperitoneal injection, the positive control drug is G-CSF, respectively fill five kinds of peroal Leucocyte increasing drugs (Qijiao Shengbai Capsule, Weixuening Granule, Compound Zaofan Pill, Berbamine and Leucogen Tablets) in the stomach, the experimental group was divided into normal control group (group A), model group (group B), positive control group (Group rhG-CSF, group C) and treatment groups (group D-H), and treatment groups were divided into Qijiao Shengbai Capsule group (group D), Weixuening Granule group (group E), Compound Zaofan Pill group (group F), Berbamine Tablet group (group G) and Leucogen Tablet group (group H). Calculate the death rate, blood routine and important visceral organ index in each group.. Results: The death rate of mice in each group has no significant difference (P>0.05). WBC of B, D, E and F groups was significantly lower than that of group A (

    Iron accumulation in the ventral tegmental area in Parkinson's disease

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    IntroductionThe ventral tegmental area (VTA) is less affected compared to substantia nigra pars compacta (SNc) in Parkinson's disease (PD). This study aimed to quantitatively evaluate iron content in the VTA across different stages of PD in order to help explain the selective loss of dopamine neurons in PD.MethodsQuantitative susceptibility mapping (QSM) data were obtained from 101 PD patients, 35 idiopathic rapid eye movement sleep behavior disorder (RBD) patients, and 62 healthy controls (HCs). The mean QSM values in the VTA and SNc were calculated and compared among the groups.ResultsBoth RBD and PD patients had increased iron values in the bilateral SNc compared with HCs. RBD and PD patients in the Hoehn–Yahr (H & Y) stage 1 did not show elevated iron values in the VTA, while PD patients with more than 1.5 H & Y staging had increased iron values in bilateral VTA compared to HCs.DiscussionThis study shows that there is no increased iron accumulation in the VTA during the prodromal and early clinical stages of PD, but iron deposition increases significantly as the disease becomes more severe
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