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1.
Schizophr Res ; 231: 115-121, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33839369

RESUMO

OBJECTIVE: The corpus callosum (CC) is known to be altered in patients with schizophrenia. However, its morphologic characteristics are less well studied in treatment-naive first-episode schizophrenia patients, as is the effect of antipsychotic treatment on this structure. METHODS: T-1 weighted MRI scans were obtained from 160 antipsychotic-naïve first-episode schizophrenia patients (AN-FES) and 155 healthy controls (HCs) before treatment initiation. Among the patients, forty-four were available for follow-up studies after one year of antipsychotic treatment, and were divided into good-outcome (n = 31) and poor-outcome subgroups (n = 13) based on whether there was a 50% reduction in Positive and Negative Symptom Scale (PANSS) total scores from baseline. A computer algorithm was applied to automatically identify the mid-sagittal plane (MSP) and obtain morphological measurement parameters of the CC. RESULTS: Compared with HCs, AN-FES patients showed a significant reduction of thickness in the posterior midbody of the CC. This deficit was correlated with severity of negative symptoms. After one year of antipsychotic treatment, there was no significant change in CC morphological measurements in schizophrenia patients, nor was there a significant difference of CC morphological measurements between good-outcome and poor-outcome subgroups at baseline or at 1-year follow-up. CONCLUSION: Thickness of the posterior midbody of the CC is reduced in the early course of schizophrenia before treatment. This alteration was not affected by antipsychotic treatment and was unrelated to treatment outcome at 1-year.

2.
Psychol Med ; : 1-9, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33436114

RESUMO

BACKGROUND: There is increasing evidence that blood oxygenation level-dependent signaling in white matter (WM) reflects WM functional activity. Whether this activity is altered in schizophrenia remains uncertain, as does whether it is related to established alterations of gray matter (GM) or the microstructure of WM tracts. METHODS: A total of 153 antipsychotic-naïve schizophrenia patients and 153 healthy comparison subjects were assessed by resting-state functional magnetic resonance imaging, diffusion tensor imaging, and high-resolution T1-weighted imaging. We tested for case-control differences in the functional activity of WM, and examined their relation to the functional activity of GM and WM microstructure. The relations between fractional anisotropy (FA) in WM and GM-WM functional synchrony were investigated as well. Then, we examined the associations of identified abnormalities to age, duration of untreated psychosis (DUP), and symptom severity. RESULTS: Schizophrenia patients displayed reductions of the amplitude of low-frequency fluctuations (ALFF), GM-WM functional synchrony, and FA in widespread regions. Specifically, the genu of corpus callosum not only had weakening in the synchrony of functional activity but also had reduced ALFF and FA. Positive associations were found between FA and functional synchrony in the genu of corpus callosum as well. No significant association was found between identified abnormalities and DUP, and symptom severity. CONCLUSIONS: The widespread weakening in the synchrony of functional activity of GM and WM provided novel evidence for functional alterations in schizophrenia. Regarding the WM function as a component of brain systems and investigating its alternation represent a promising direction for future research.

3.
Schizophr Res ; 228: 241-248, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33486391

RESUMO

Schizophrenia is a serious mental illness for which the mainstay of treatment is antipsychotics. Up to 30% of schizophrenia patients show limited response to antipsychotics. Identifying these patients before treatment could guide individualized treatment for improving outcomes in those not likely to show robust benefit from antipsychotics. Diffusion tensor imaging was performed with 56 drug-naïve first-episode schizophrenia patients and 69 matched healthy controls. Patients were followed clinically after one-year of antipsychotic treatment and classified at that point into groups of 17 poor outcome and 39 good outcome patients based on whether they showed at least a 50% reduction of Positive and Negative Syndrome Scale (PANSS) scores from baseline. Tract-based spatial statistics were applied to assess white matter microstructure in the two patient subgroups and healthy controls. Poor outcome patients showed reduced pretreatment fractional anisotropy (FA) in left cingulum and anterior thalamic radiation and increased FA in right superior and inferior longitudinal fasciculus compared with good outcome patients. FA in each of these four tracts was decreased in both patient subgroups relative to healthy controls. Considered together, the four altered tracts showed promising ability to differentiate poor from good outcome patients (sensitivity = 74.4%, specificity = 95.2%, AUC = 0.90, p < 0.001), and superior prediction of clinical outcome to baseline PANSS scores (p < 0.015). Prediction of outcomes using DTI features was not related to duration of untreated psychosis. Baseline alterations in white matter integrity may identify schizophrenia patients less likely to respond to treatment, which could be useful information for stratification in clinical trials and for individualized treatment planning.

4.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(3): 480-486, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597090

RESUMO

The study aims to investigate whether there is difference in pre-treatment white matter parameters in treatment-resistant and treatment-responsive schizophrenia. Diffusion tensor imaging (DTI) was acquired from 60 first-episode drug-naïve schizophrenia (39 treatment-responsive and 21 treatment-resistant schizophrenia patients) and 69 age- and gender-matched healthy controls. Imaging data was preprocessed via FSL software, then diffusion parameters including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were extracted. Besides, structural network matrix was constructed based on deterministic fiber tracking. The differences of diffusion parameters and topology attributes between three groups were analyzed using analysis of variance (ANOVA). Compared with healthy controls, treatment-responsive schizophrenia showed altered white matter mainly in anterior thalamus radiation, splenium of corpus callosum, cingulum bundle as well as superior longitudinal fasciculus. While treatment-resistant schizophrenia patients showed white matter abnormalities in anterior thalamus radiation, cingulum bundle, fornix and pontine crossing tract relative to healthy controls. Treatment-resistant schizophrenia showed more severe white matter abnormalities in anterior thalamus radiation compared with treatment-responsive patients. There was no significant difference in white matter network topological attributes among the three groups. The performance of support vector machine (SVM) showed accuracy of 63.37% in separating the two patient subgroups ( P = 0.04). In this study, we showed different patterns of white matter alterations in treatment-responsive and treatment-resistant schizophrenia compared with healthy controls before treatment, which may help guiding patient identification, targeted treatment and prognosis improvement at baseline drug-naïve state.


Assuntos
Esquizofrenia , Substância Branca , Anisotropia , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão , Humanos , Esquizofrenia/diagnóstico por imagem
5.
Neuropsychopharmacology ; 45(8): 1369-1379, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32353861

RESUMO

Schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD) are heritable psychiatric disorders with partially overlapping genetic liability. Shared and disorder-specific neurobiological abnormalities associated with familial risk for developing mental illnesses are largely unknown. We performed a meta-analysis of structural brain imaging studies in relatives of patients with SCZ, BD, and MDD to identify overlapping and discrete brain structural correlates of familial risk for mental disorders. Search for voxel-based morphometry studies in relatives of patients with SCZ, BD, and MDD in PubMed and Embase identified 33 studies with 2292 relatives and 2052 healthy controls (HC). Seed-based d Mapping software was used to investigate global differences in gray matter volumes between relatives as a group versus HC, and between those of each psychiatric disorder and HC. As a group, relatives exhibited gray matter abnormalities in left supramarginal gyrus, right striatum, right inferior frontal gyrus, left thalamus, bilateral insula, right cerebellum, and right superior frontal gyrus, compared with HC. Decreased right cerebellar gray matter was the only abnormality common to relatives of all three conditions. Subgroup analyses showed disorder-specific gray matter abnormalities in left thalamus and bilateral insula associated with risk for SCZ, in left supramarginal gyrus and right frontal regions with risk for BD, and in right striatum with risk for MDD. While decreased gray matter in right cerebellum might be a common brain structural abnormality associated with shared risk for SCZ, BD, and MDD, regional gray matter abnormalities in neocortex, thalamus, and striatum appear to be disorder-specific.

6.
Transl Psychiatry ; 10(1): 136, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398765

RESUMO

Though gray matter deficits have been consistently revealed in chronic treated schizophrenia, it is still not clear whether there are different brain alterations between chronic never treated and treated patients. To explore the different patterns of gray matter alterations among chronic never treated patients and those treated with monotherapy, we recruited 35 never-treated chronic schizophrenia patients with illness durations ranging from 5 to 48 years, 20 illness duration-matched risperidone monotherapy and 20 clozapine monotherapy patients, and 55 healthy controls. GM (surface area, cortical thickness, and cortical volume) measures were extracted and compared using ANCOVA across the four groups followed by post hoc tests. Relative to controls, both treated and never-treated chronic schizophrenia patients showed reduced GM mainly involving the bilateral medial and rostral middle frontal, left banks superior temporal sulcus, left fusiform, and left pericalcarine cortex and increased in the left cuneus. Compared with the untreated patient group, the two treated groups showed reductions mainly in the bilateral prefrontal, temporal, and left inferior parietal lobules. The clozapine monotherapy patients demonstrated more severe decreases in the bilateral prefrontal cortex and left cuneus and less severe decreases in the left ventral temporal lobe than risperidone monotherapy patients. These findings provide new insights into the long-term effects of antipsychotic treatment on gray matter alterations in schizophrenia patients. Furthermore, the characteristic findings of reductions in the inferior parietal lobule might be specific for long-term antipsychotic treatment, which could be a possible target for medication development in the future.

7.
J Magn Reson Imaging ; 52(3): 752-763, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31859423

RESUMO

BACKGROUND: Schizophrenia is one of the most severe psychiatric disorders and dysfunction of gray matter (GM) has been usually investigated by resting-state functional (f)MRI. However, functional organization of white matter (WM) in chronic schizophrenia remains unclear. PURPOSE: To investigate the WM functional alterations in chronic never-treated schizophrenia and the effects of long-term antipsychotic treatment. STUDY TYPE: Prospective. SUBJECTS: Twenty-five never-treated, 41 matched antipsychotic-treated schizophrenia, and 25 healthy comparison subjects. FIELD STRENGTH/SEQUENCE: Resting state (rs)-fMRI, T1 -weighted images (T1 WI), and diffusion tensor imaging (DTI) covering the whole brain were acquired with a 3.0T scanner. ASSESSMENT: Amplitude of low-frequency fluctuations (ALFF) in WM and the correlation coefficients between WM and GM were examined and compared among the three participant groups by two reviewers independently. Independent component analysis (ICA) was added to evaluate WM-fMRI signals. Statistical Tests: Analysis of covariance (ANCOVA); Pearson correlation analysis. RESULTS: Never-treated patients demonstrated lower ALFF in splenium of corpus callosum (SCC) relative to treated patients and controls (P < 0.001, false discovery rate [FDR]-corrected). While the extracted independent component also located in SCC and showed significantly decreased connectivity in never-treated patients when compared to controls (P < 0.05, FDR-corrected). The correlation coefficients of WM-GM displayed greater reductions in the genu of corpus callosum (GCC), pontine crossing tract (PC), bilateral cingulum (hippocampus) (CGH), and bilateral corticospinal tract (CST) in treated patients relative to controls (P < 0.05, FDR-corrected). DATA CONCLUSION: These findings provide new insight into WM functional alterations over the long-term course of schizophrenia with and without the potential effects of antipsychotic medication. Functional change and abnormal connectivity in SCC were both found greater in untreated patients than treated patients relative to healthy controls, suggesting that long-term antipsychotic treatment may show some protective effects on WM functional organization. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:752-763.

8.
J Comput Assist Tomogr ; 43(1): 22-28, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30188358

RESUMO

PURPOSE: The aim of this study was to evaluate the potential value of low-dose multimodal computed tomography (CT) in predicting prognosis of acute ischemic stroke (AIS) within 6 hours. METHODS: The admission "one-stop-shop" multimodal CT examination, including noncontrast CT (NCCT), low-dose CT perfusion, and CT angiography (CTA), was performed in patients with symptoms of stroke within 6 hours. Noncontrast CT, CTA source image (CTA-SI), cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and mean transit time (MTT) maps were studied using Alberta Stroke Program Early CT Score (ASPECTS). The regional leptomeningeal collateral (rLMC) score (0-20) was dichotomized into 2 groups: good (11-20) and poor (0-10) rLMC. Poor functional outcomes were defined by a modified Rankin scale score of 3 to 6. RESULTS: One hundred forty-four patients were ultimately selected; 43.8% of them showed poor functional outcomes. They had lower ASPECTSs on NCCT, CTA-SI, CBV, CBF, TTP, and MTT, and poor rLMC was more frequently associated with poor functional outcomes (all P < 0.001). In the multivariate analysis for AIS patients with conservative treatment, CTA-SI-ASPECTS 6 or less (odds ratio [OR], 5.9; 95% confidence interval [95% CI], 1.9-18.4; P = 0.002) and poor collaterals (OR, 5.0; 95% CI, 1.3-15.4; P = 0.017), CBV-ASPECTS 6 or less (OR, 8.0; 95% CI, 2.7-24.0; P < 0.001), CBF-ASPECTS 4 or less (OR, 8.0; 95% CI, 2.0-31.5; P = 0.003), MTT-ASPECTS≤3 (OR, 5.8; 95% CI, 1.8-18.1; P = 0.003), TTP-ASPECTS 4 or less (OR, 5.0; 95% CI, 1.6-15.1; P = 0.005), and NCCT-ASPECTS 8 or less (OR, 5.9; 95% CI, 1.7-20.4; P = 0.005) were significantly associated with poor functional outcome. In the multivariate analysis for AIS patients with thrombolysis, CTA-SI-ASPECTS 6 or less (OR, 27.5; 95% CI, 2.9-262.3; P = 0.004), poor collaterals (OR, 28.0; 95% CI, 2.8-283.0; P < 0.028), and CBV-ASPECTS 6 or less (OR, 18.0; 95% CI, 3.0-107.7; P = 0.002) were associated with poor functional outcomes. Furthermore, the area under the curve (AUC) of the combination of CTA-SI-ASPECTS 6 or less, poor collaterals, and CBV-ASPECTS 6 or less (AUC, 0.87) was greater than that for any single parameter alone: CTA-SI-ASPECTS 6 or less (AUC, 0.80; P < 0.001), poor collaterals (AUC, 0.76; P < 0.001), and CBV-ASPECTS 6 or less (AUC, 0.81; P = 0.002). CONCLUSIONS: The combination of CTA-SI-ASPECTS, collaterals, and CBV-ASPECTS may improve predictive power compared with a single parameter alone.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Imagem Multimodal/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Doença Aguda , Idoso , Isquemia Encefálica/complicações , Angiografia Cerebral , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Masculino , Prognóstico , Estudos Prospectivos , Doses de Radiação , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações
9.
Nanoscale ; 8(45): 19161-19173, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27827501

RESUMO

A facile and efficient ligand-triggered electrostatic self-assembly strategy has been developed to fabricate a series of Au/CdS nanosheet (Ns) (Au-CdS Ns) nanocomposites with varied weight addition ratios of Au nanoparticles (NPs) by judiciously utilizing the intrinsic surface charge properties of assembly units, through which uniform dispersion and controllable deposition of Au NPs on the CdS Ns were achieved. Versatile probe reactions including photocatalytic oxidation of an organic dye pollutant, selective photocatalytic reduction of aromatic nitro compounds and photocatalytic hydrogen production reactions under visible light irradiation and ambient conditions were used to systematically evaluate the photoredox performances of the as-assembled well-defined Au-CdS Ns nanocomposites. It was unveiled that the photoactivities of Au-CdS Ns nanocomposites strongly depend on the weight addition ratio of Au NPs and the addition of an excess amount of Au NPs is detrimental to the separation of photogenerated charge carriers from CdS Ns. With the optimum addition amount of Au NPs (1 wt%), it was found that spontaneous assembly of Au NPs on the CdS Ns remarkably prolonged the lifetime of the photogenerated charge carriers from CdS Ns under visible light irradiation, thus resulting in significantly enhanced photocatalytic redox activities of Au-CdS Ns nanocomposites compared with those of CdS Ns. The crucial role of Au NPs in the photoredox reactions as efficient electron traps rather than plasmonic sensitizers was determined. Moreover, predominant active species responsible for the photocatalytic process were unambiguously determined and a possible photocatalytic mechanism was elucidated. It is anticipated that our work could open up a new avenue to rationally prepare various 2D semiconductors-metal nanocomposites by utilizing such a simple and efficient self-assembly strategy for extensive photocatalytic applications in a myriad of fields.

10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(9): 2566-9, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24369673

RESUMO

The present paper described a triple-wavelength visible spectroscopic method for the determination of iron content in lignocellulosic materials. After the sample was pretreated with acidic hydrolysis method under selected conditions, the color agent, 1, 10-phenanthroline monohydrate, was added in the filtrate and then measured by a triple-wavelength spectroscopic method at wavelengths of 416, 510 and 700 nm, from which the iron contents of the sample can be calculated. The results showed that this method can efficiently deduct the influences of acidic soluble lignin and furfural compounds generated during the sample pretreatment and baseline drift caused by the tiny particles in the filtrates. It not only has a good measurement precision but also is accurate, in which the relative differences of the results obtained by the present method and ICP-OES method is less than 5%. The method is simple and practical, and suitable for industrial applications.


Assuntos
Ferro/análise , Lignina/química , Análise Espectral , Furaldeído
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