Biomedical subjects

Dai Zhang

Publications and source records attributed to Dai Zhang.

24 records · Page 2Linked to original sources

PubMed2003

Association study of the human FZD3 locus with schizophrenia.

The FZD3 protein is a transmembrane receptor for secreted Wnt glycoproteins involved in the Wnt signal transduction cascades. The alteration of Wnt signal transduction cascades has been thought to be involved in producing the cytoarchitectural defects observed in schizophrenia. Because the human FZD3 gene is mapped to chromosome 8p21, which is a potential region containing a gene for schizophrenia, it may play a role in conferring susceptibility to the disease. This study was conducted with the detection of three single nucleotide polymorphisms (SNPs) located within the FZD3 locus by using the polymerase chain reaction-based restriction fragment length polymorphism (RFLP) analysis among 246 schizophrenic family trios of Chinese Han descent.The transmission disequilibrium test (TDT) demonstrated that the three SNPs all showed a preferential transmission with a p value ranging from.0003-.000007. The global chi-squared test for haplotype transmission also showed a strong association (chi(2) = 48.84, df = 7, p <.000001).The strong association between the FZD3 locus and schizophrenia suggests that the gene itself may play a role in underlying schizophrenia, although a nearby gene responsible for predisposing to the illness cannot be ruled out.

Chromosomes, Human, Pair 8↗

PubMed2003

Abnormal anterior cingulum in patients with schizophrenia: a diffusion tensor imaging study.

Diffusion tensor imaging (DTI) can non-invasively examine the molecular diffusion of water in vivo and directly reflects the anatomical integrity of neural fibers in white matter. Fractional anisotropy (FA) can be calculated from DTI data, and utilized to evaluate white matter integrity. DTI was performed on 30 patients with schizophrenia and 19 healthy controls, and their FA values were subsequently measured in multiple brain regions. Statistical analyses revealed that FA values were decreased in the anterior cingulum of schizophrenia subjects. There were no significant differences between patients and controls in any other regions. This study supports the hypothesis that schizophrenia is associated with abnormal white matter integrity of the anterior cingulum.

Adult↗

PubMed2003

A diffusion tensor imaging study of middle and superior cerebellar peduncle in male patients with schizophrenia.

Many studies have confirmed that the cerebellum takes part in higher-order cognitive coordination; profound fibers projecting to and from the cerebellum underlie its cognitive function. Since the superior and middle cerebellar peduncles are the main pathways of neural fibers in the cerebellum, these structures became the focus of our interest in evaluating the cognitive dysfunction reported in schizophrenia. Diffusion tensor imaging (DTI) was used to examine the anatomical integrity of the neural fibers in the superior and middle cerebellar peduncles. DTI was performed on 29 patients and 20 normal controls; we subsequently calculated the fractional anisotropy and mean diffusivity in these regions. Statistical analysis revealed that there was no significant difference between patients with schizophrenia and our matched control group. No structural abnormalities were detected in the white matter of the superior and middle cerebellar peduncles.

Adult↗

PubMed2003

[Deletion mutation of beta-amyloid precursor protein decreases the secretion of beta-amyloid in SH-SY5Y neuroblastoma cells].

OBJECTIVE: To explore the effect of A beta secretion lacking exons 2 and 3 of APP695 (delta APP695) on SH-SY5Y neuroblastoma cells. METHODS: APP695 cDNA and delta APP695 cDNA eukaryotic expression vectors were constructed by gene recombination. Immunoprecipitation Western blotting was used to analyse the A beta secretion and MTT assay to observe the cell viability's change after being stably transfected with the plasmids by lipofectamine method. RESULTS: Stable transfectants were selected in 0.6 g.L-1 G418. delta APP695 cDNA construct transfection decreased significantly the production of beta amyloid in the SH-SY5Y compared with APP695 cDNA construct. It did not affect the cell viability by MTT method. CONCLUSION: This result suggests that the alternative splicing of APP exons 2 and 3 modulates the secretion of A beta by influencing the processing of APP.

Amyloid beta-Peptides↗

PubMed2003

Association study between interleukin-1beta gene (IL-1beta) and schizophrenia.

An increasing amount of evidence suggests that the pathophysiology of schizophrenia is associated with the abnormal immune system, and cytokines may be important in schizophrenia. Among these cytokines, interleukin-1beta may play a role in the pathogenesis of the disease. In the present study, we investigated the genetic association between a TaqI polymorphism in interleukin-1beta gene (IL-1beta) and schizophrenia by restriction fragment length polymorphism (RFLP) analysis among 132 Chinese families of Han descent. The transmission disequilibrium test (TDT) did not demonstrate an allelic association with schizophrenia. Our results suggested that the TaqI polymorphism in IL-1beta gene might not confer increased susceptibility for schizophrenia.

Adolescent↗

PubMedDate not supplied

Diagnostic utility of neuropsychological performance and quantitative MRI-based measurement in Alzheimer disease.

This study was designed to examine the roles of the characteristic cognitive indicators and specific MRI-based measurements in the differential diagnoses of Alzheimer disease (AD), vascular dementia (VaD), and normal aging. Fifty-two probable AD patients were recruited for the study. Twenty-seven VaD patients and 35 age-matched normal older adults (NC) were included as controls. All subjects underwent a battery of standardized neuropsychological tests. The MRI-based quantification technique was used to measure the volumes and T2 relaxation time (T2) of medial temporal lobe structures. Stepwise discriminant analyses showed cognitive indicators had a sensitivity ranging from 82% to 100% and specificity from 82% to 97% for differentiating AD from non-AD cases (VaD and normal controls), and the quantitative MRI-based measurements of medial temporal lobe structures correctly classified AD cases from non-AD cases with sensitivity from 80% to 96% and specificity from 83% to 97%. ROC curve analyses showed that the combination of cognitive and MRI measurements slightly increased the diagnostic accuracy of AD. The results suggest that both cognitive indicators and MRI-based medial temporal lobe measurements may be useful in differentiating AD from VaD and normal older adults. The combination of these possible indicators is promising in the early diagnosis of AD.

Aged↗