Aberrant interhemispheric functional and structural connectivity in heroin-dependent individuals.

Models of heroin addiction emphasize the role of disrupted frontostriatal circuitry supporting cognitive control processes. However, heroin addiction-related alterations in functional and structural interactions among brain regions, especially between the cerebral hemispheres, are rarely examined directly. Resting-state functional magnetic resonance imaging (fMRI) approaches, which reveal patterns of coherent spontaneous fluctuations in the fMRI signal, offer a means to quantify directly functional interactions between the hemispheres. The corpus callosum (CC), which connects homologous regions of the cortex, is the major conduit for information transfer between the cerebral hemispheres and represents a structural connectivity index between hemispheres. We compared interhemispheric voxel-mirrored homotopic connectivity (VMHC) and CC volume between 45 heroin dependent-individuals (HDIs) and 35 non-addict individuals. We observed significant reduction of VMHC in a number of regions, particularly the striatum/limbic system regions, and significant decrease in splenium and genu sub-regions of CC in HDI. Importantly, within HDI, VMHC in the dorsal lateral prefrontal cortex (DLPFC) correlated with genu CC volume, VMHC in the putamen, VMHC in the DLPFC and genu CC volume and splenium CC volume were negatively correlated with heroin duration and impulsivity traits. Further analyses demonstrated that impairment of VMHC of bilateral DLPFC partially mediated the association between genu CC volumes decreased and increased impulsivity in HDI. Our results reveal a substantial impairment of interhemispheric coordination in the HDI. Further, interhemispheric connectivity correlated with the duration of heroin abuse and higher impulsivity behavior in HDI. Our findings provide insight into a heroin addicts' related pathophysiology and reinforce an integrative view of the interhemispheric cerebral functional and structural organization.

Larger corpus callosum and reduced orbitofrontal cortex homotopic connectivity in codeine cough syrup-dependent male adolescents and young adults.

OBJECTIVES: To characterize interhemispheric functional and anatomical connectivity and their relationships with impulsive behaviour in codeine-containing cough syrup (CCS)-dependent male adolescents and young adults. METHODS: We compared volumes of corpus callosum (CC) and its five subregion and voxel-mirrored homotopic functional connectivity (VMHC) in 33 CCS-dependent male adolescents and young adults and 38 healthy controls, group-matched for age, education and smoking status. Barratt impulsiveness scale (BIS.11) was used to assess participant impulsive behaviour. Abnormal CC subregions and VMHC revealed by group comparison were extracted and correlated with impulsive behaviour and duration of CCS use. RESULTS: We found selective increased mid-posterior CC volume in CCS-dependent male adolescents and young adults and detected decreased homotopic interhemispheric functional connectivity of medial orbitofrontal cortex (OFC). Moreover, impairment of VMHC was associated with the impulsive behaviour and correlated with the duration of CCS abuse in CCS-dependent male adolescents and young adults. CONCLUSIONS: These findings reveal CC abnormalities and disruption of interhemispheric homotopic connectivity in CCS-dependent male adolescents and young adults, which provide a novel insight into the impact of interhemispheric disconnectivity on impulsive behaviour in substance addiction pathophysiology. KEY POINTS: • CCS-dependent individuals (patients) had selective increased volumes of mid-posterior corpus callosum • Patients had attenuated interhemispheric homotopic FC (VMHC) of bilateral orbitofrontal cortex • Impairment of VMHC correlated with impulsive behaviour in patients • Impairment of VMHC correlated with the CCS duration in patients.

Comparative proteomic analysis of melanosis coli with colon cancer.

The present study aimed to investigate the proteomic difference between melanosis coli (MC) alone and melanosis coli with colon cancer (MCCC). Protein expression in patients with different diseases was analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/TOF-MS). A total of 14 protein differences with a confidence level of >95% were found. There were six differences between MC and normal tissues, in which two proteins exhibited upregulated expression levels and four proteins exhibited downregulated expression levels in MC. Furthermore, one protein was expressed only in MC (P<0.05). In addition, there were differences in the expression of eight proteins between MC and MCCC tissues, in which one protein had an upregulated expression in MC tissues and seven proteins had an upregulated expression in MCCC tissues. Furthermore, two proteins were only expressed in MCCC tissues (P<0.05). Eight proteins were identified using mass spectrometry and database search. In conclusion, comparative proteomics accurately displayed the expression differences in eight proteins between MC, MCCC and normal colon tissues.

The impulsivity behavior is correlated with prefrontal cortex gray matter volume reduction in heroin-dependent individuals.

PURPOSE: Chronic exposure to heroin induced cerebral structural abnormalities may underlie heroin-related behaviors. The aim of this study was to: (1) identify cerebral structural abnormalities in heroin-dependent individuals (HDIs) by an automated and unbiased morphometric technique. (2) Define the correlation between these cerebral structural abnormalities and the impulsivity characteristic in HDIs. METHODS: 24 HDIs and 24 control subjects were completed with (1) high resolution structural magnetic resonance imaging scanning and analysis of gray matter volume using voxel-based morphometry implemented in Statistical Parametric Mapping and (2) a Chinese translation Barratt Impulsiveness Scale-11 questionnaire survey. Differences in regional gray matter volume were tested using an analysis of covariance model, co-varying for global gray matter and age. Statistical maps were set at p<0.05, corrected for multiple comparisons. The abnormal brain regions were correlated with the duration of heroin use and impulsivity scores. RESULTS: After adjusting for effects of age and total gray matter volume, cortical gray matter volume in the bilateral medial prefrontal cortex, bilateral dorsal lateral prefrontal cortex, and right fusiform cortex were significantly reduced in HDIs. Moreover, the gray matter volume in prefrontal cortex that showed group differences was negatively correlated with the duration of heroin use and negatively correlated with the impulsivity characteristic in HDIs. CONCLUSION: These findings reveal the prefrontal cortex was impaired in HDIs, meanwhile, indicate the changes in gray matter volume are relating to the duration of heroin use and the impulsivity characteristic of the HDIs.

Regional homogeneity changes in heroin-dependent individuals: resting-state functional MR imaging study.

PURPOSE: To identify heroin-related modulations of neural activity in the resting state in heroin-dependent individuals (HDIs) by using resting-state functional magnetic resonance (MR) imaging and a regional homogeneity method and to investigate whether these changes of neural activity can be related to duration of heroin use and to decision-making deficits in HDIs. MATERIALS AND METHODS: This prospective study was approved by the appropriate ethics committee, and written informed consent was obtained from each participant. Thirty-one HDIs receiving methadone-maintained treatment and 24 control subjects participated. Resting-state functional MR imaging was performed by using a gradient-echo echo-planar imaging sequence. Regional homogeneity was calculated by using software. Voxel-based analysis of the regional homogeneity maps between control and HDI groups was performed with two-sample t tests by using software. Statistical maps were set at P less than .05 and were corrected for multiple comparisons. The Iowa gambling task (IGT) was used to assess participant decision making during uncertainty. Abnormal clusters revealed by group comparison were extracted and correlated with behavioral performance at the IGT and with duration of heroin use. RESULTS: Regional homogeneity was diminished in the bilateral medial orbitofrontal cortex (OFC), bilateral dorsal medial thalamus, bilateral cuneus, and lingual gyrus in HDIs compared with control subjects. There were negative correlations between mean regional homogeneity in the medial OFC, bilateral cuneus, and lingual gyrus and duration of heroin use. There was a positive correlation between mean regional homogeneity in the medial OFC and performance level at the IGT. CONCLUSION: The present study reveals resting-state abnormalities in HDIs that may lead to further improvement of the understanding of the neural substrates of cognitive impairment in HDIs.

[Value of computed tomography and magnetic resonance imaging in diagnosis and differential diagnosis of small hepatocellular carcinoma].

OBJECTIVE: To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of small hepatocellular carcinoma to improve the accuracy in the diagnosis. METHODS: This retrospective analysis involved 41 patients with small hepatocellular carcinoma cases confirmed by pathological examination of the biopsy samples or follow-up. These patients were assessed for CT and MRI findings including lesion size, density or signal intensity, enhancement patterns, and presence of tumor capsules. RESULTS: On unenhanced CT images, small hepatocellular carcinomas were displayed mainly as low-density masses, and the majority of tumors presented with low signal intensity on T1-weighted unenhanced MR images with increased signal intensity on T2-weighted images in comparison with the surrounding liver parenchyma. Most of tumors showed intense enhancement during the arterial phase (CT in 15 cases and MRI in 13 cases), but some appeared isointense to the liver parenchyma (CT in 4 cases and MRI in 4 cases). In portal and delayed phases, the tumors typically had lower signal intensity than that of the surrounding liver tissues (CT in 25 cases and MRI in 12 cases) with enhancement of the tumor capsules (13 cases). CONCLUSION: Dynamic enhanced scanning can be more informative of the pathology and blood supply of small hepatocellular carcinoma. Early and late arterial phase imaging may help in detecting the small lesions and in making differential diagnosis.