Brain structure alterations in depression: Psychoradiological evidence.

Depression is the leading cause of disability around the world, but little is known about its pathology. Currently, the diagnosis of depression is made based on clinical manifestations, with little objective evidence. Magnetic resonance imaging (MRI) has been used to investigate the pathological changes in brain anatomy associated with this disorder. MRI can identify structural alterations in depressive patients in vivo, which could make considerable contributions to clinical diagnosis and treatment. Numerous studies that focused on gray and white matter have found significant brain region alterations in major depressive disorder patients, such as in the frontal lobe, hippocampus, temporal lobe, thalamus, striatum, and amygdala. The results are inconsistent and controversial because of the different demographic and clinical characteristics. However, some regions overlapped; thus, we think that there may be a "hub" in MDD and that an impairment in these regions contributes to disease severity. Brain connections contain both structural connections and functional connections, which reflect disease from a different view and support that MDD may be caused by the interaction of multiple brain regions. According to previous reports, significant circuits include the frontal-subcortical circuit, the suicide circuit, and the reward circuit. As has been recognized, the pathophysiology of major depressive disorder is complex and changeable. The current review focuses on the significant alterations in the gray and white matter of patients with the depressive disorder to generate a better understanding of the circuits. Moreover, identifying the nuances of depressive disorder and finding a biomarker will make a significant contribution to the guidance of clinical diagnosis and treatment.

[Positron emission tomography for molecular imaging of prostate cancer].

Prostate cancer is the most common malignancy in the urinary system of males. The remarkable biological and clinical heterogeneity of prostate cancer poses challenges to the initial diagnosis, differential diagnosis, treatment, and prognosis of the disease. Positron emission tomography/computed tomography (PET/CT) is an ideal imaging tool for noninvasive interrogation of underlying tumor biology. Recently, there are a variety of molecular imaging paths and radiopharmaceuticals for the diagnosis and treatment of prostate cancer. This article reviews the current state and prospects of the application of PET in the diagnosis of prostate cancer.

Localization of cerebral functional deficits in treatment-naive, first-episode schizophrenia using resting-state fMRI.

BACKGROUND: Spontaneous low-frequency fluctuations (LFF) in the blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal have been shown to reflect cerebral spontaneous neural activity, and the present study attempts to explore the functional changes in the regional brain in patients with schizophrenia using the amplitude of the BOLD signals. METHODS: A total of 66 treatment-naïve, first-episode schizophrenia (FES) patients and 66 normal age- and sex-matched controls were recruited. Resting-state fMRIs were obtained using a gradient-echo echo-planar imaging sequence. The amplitude of LFF (ALFF) was calculated using REST software. Voxel-based analysis of the ALFF maps between control and patient groups was performed with twos-sample t-tests using SPM2. RESULTS: Compared to the controls, the FES group showed significantly decreased ALFF in the medial prefrontal lobe (MPFC) and significant increases in the ALFF in the left and right putamen. Significant positive correlations were observed between ALFF values in the bilateral putamen in both the patient and control groups. CONCLUSIONS: Alterations of the ALFF in the MPFC and putamen in FES observed in the present study suggest that the functional abnormalities of those areas are at an early stage of the disease.

[Construction and expression of replication-deficient recombinant adenovirus vector with hNET gene by adeasy-1 system].

OBJECTIVE: To construct and identify the recombinant replication deficient adenovirus vector which codes for human Norepinephrine Transporter (hNET) gene by using the method of homogenous recombination in bacteria. METHODS: hNET gene was obtained from the recombinant plasmid pCMV5 via Kpn I + Xba I digestion, and subcloned into E1 deleted expression plasmid pAdtrack-CMV shuttle vector, forming transfer vector pAdtrack-CMV-hNET. Then it was linearized with Pme I followed by homologous recombination with bone plasmid pAdEasy-1 in BJ5183 cells to generate recombinant plasmid Ad-hNET. The DNA of identified Ad-hNET was digested with Pac I and transfected to HEK293 cells by liposome-mediated method to package recombinant adenovirus. The PCR technique was applied to detect the target gene and Western Blotting to verify the expression of hNET. The titre of the Ad-hNET was measured with the aid of green fluorescence protein (GFP) expression after multiplication and purification. RESULTS: By sequencing, it was confirmed that the product was the gene of hNET. PCR test, restriction endonuclease digestion and Western Blotting confirmed the successful construction of the recombinants Ad-hNET. The titre of purified recombinant adenovirus Ad-hNET was 1.2 X 10(10) pfu/mL. CONCLUSION: The recombinant adenovirus with the hNET gene was constructed successfully. It will be helpful for the further investigation of its potentiality to be applied in the tumors targeted therapeutic strategy.

Rhenium-188 labelled meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl] porphyrin for targeted radiotherapy: preliminary biological evaluation in mice.

PURPOSE: This study focusses on a promising carrier system for therapeutic and imaging purposes using meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl] porphyrin (T(3,4)CPP). To assess its potential for clinical use, we labelled T(3,4)CPP with (188)Re and analysed some kinetic biodistribution parameters after intravenous injection in mice. MATERIALS AND METHODS: T(3,4)CPP was synthesized and labelled with (188)Re. Normal Kunming (KM) mice and melanoma- or hepatoma-bearing BALB/c nude mice were injected intravenously with 5.55 MBq (188)Re-labelled T(3,4)CPP and sacrificed at 0.5, 2, 4, and 24 h and 8, and 24 h, respectively. RESULTS: The (188)Re-T(3,4)CPP yield was more than 95% with specific activity 16.9 GBq (mol)(-1), and Vitamin C (VC) could increase its stability in vitro. In normal KM mice, (188)Re-T(3,4)CPP had fast blood clearance (approximately 99%, 24 h postinjection), low retention in the vital organs and hepatotropic characteristics. In nude mice, more than 4.4 and 6.1% uptake per gram of tumour (%ID g(-1)) at 8 h postinjection was in melanoma and hepatoma, respectively; this remained as high levels after 24 h as 4.6 and 6.5%, respectively. At 8 h, the tumour/blood and tumour/muscle (T/M) ratios in melanomas and hepatoma bearing mice were 7.3, 13,and 7.0, 20, respectively. Twenty-four hours later, these high ratios still continued in existence which were 9.6, 19 and 10, 25, respectively. CONCLUSION: The results obtained in this study indicate that (188)Re-T(3,4)CPP has better tumour affinity and retainable accumulation characteristics in carcinoma which can potentially be used for tumour-targeted radiotherapy.

[Preliminary application of 99Tc(m)-MIBI scintigraphy for judgment of bone malignant and benign lesions].

OBJECTIVE: The aim of this study was to assess the value of Tc-99m-hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy diagnosing the malignant and benign bone lesions in comparison with a conventional bone tracer 99Tm-methylene-diphosphonate (MDP). METHODS: 99Tc(m)-MDP three-phase bone scintigraphy and 99Tc(m)-MIBI dynamic and quiet states scintigraphy were obtained from 39 patients with proved malignant diseases or suspected bone metastases after bolus injected intravenously radiopharmaceuticals, respectively. The results were compared with using film reading and regions of interesting (ROI) technique. RESULTS: 139 bone metastases were confirmed in 169 lesions. The sensitivity of 99Tc(m)-MDP or 99Tc(m)-MIBI scintigraphy was 90.3% or 68.4% (P < 0.05), respectively; the specificity was 33.3% or 96.7% (P < 0.05), respectively;the false positive rate was 6.71% or 1.04%. No statistical difference was appeared in both malignant tumors and benign lesions with 99Tc(m)-MDP scintigraphy. However, while with 99Tc(m)-MIBI scintigraphy, there were significant statistical difference (P < 0.05) both in malignant tumors and benign lesions. 99Tc(m)-MIBI scintigraphy could early detect 17 bone metastases and proved 11 lesions to be benign bone foci and 2 to be pathologic bone fractures. CONCLUSION: Although 99Tc(m)-MIBI scintigraphy has lower general sensitivity than 99Tc(m)-MDP scintigraphy, it has higher specificity, lower false positive rate and can detect lesions early and judge the quality, which may be helpful in the evaluation and strategy of clinical therapy for bone metastases.