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Biomedical subjects

Biao Chen

Publications and source records attributed to Biao Chen.

At least 37 records · Page 2Linked to original sources
PubMed2005

Mutation analysis of small heat-shock protein 22 gene in Chinese patients with Charcot-Marie-Tooth disease.

OBJECTIVE: To study the characteristics of the mutation of small heat-shock protein 22 (HSP22) gene in Chinese patients with Charcot-Marie-Tooth (CMT) disease. METHODS: A CMT2L proband with 423(G--> T) mutation in HSP22 gene had been studied and reported by the present authors. In this study, mutation analysis of HSP22 gene was performed using polymerase chain reaction and DNA direct sequencing in 114 CMT probands. RESULTS: In the 114 CMT probands, a 582(C--> T)(T194T)samesense mutation was found in two unrelated families. CONCLUSION: The rate of HSP22 gene mutation in Chinese patients with CMT is as low as 0.87%(1/115).

Asian People↗
PubMed2005

[Mutation analysis of small heat shock protein 27 gene in Chinese patients with Charcot-Marie-Tooth disease].

OBJECTIVE: To investigate the features of small heat shock protein 27 (HSP27) gene mutation in Chinese patients with Charcot-Marie-Tooth disease (CMT). METHODS: DNA samples from 114 CMT probands were screened for mutations in HSP27 gene by polymerase chain reaction and direct sequencing, and haplotype analysis was further carried out on the mutation detected families. RESULTS: One missense mutation C379T was detected in 4 autosomal dominant CMT2 families. Haplotype analysis indicated that the 4 families probably had a common ancestor. CONCLUSION: To the authors' knowledge, this is the first report of HSP27 gene mutation in Chinese patients with CMT, but it may be not common(0.90%). The C379T mutation in HSP27 gene also causes CMT2 except for distal hereditary motor neuropathy, thus providing further evidence that even the same mutation in the same gene may lead to distinct phenotypes.

Asian People↗
PubMed2005

[A study on PARKIN gene in three pedigrees with autosomal recessive early-onset Parkinson's disease].

OBJECTIVE: To detect the possible relationship between PARKIN gene and the Chinese pedigree with autosomal recessive early-onset Parkinson's disease(AREP). METHODS: Clinical examination was carried out in 6 patients from 3 Chinese pedigrees with AREP and their 23 family members. PCR amplification of all exons of PARKIN gene was performed. The PCR products were analyzed by denaturing high-performance liquid chromatography(DHPLC) to screen for point mutation and polymorphism. And in the samples with abnormal DHPLC result, further sequencing was conducted to confirm the type of mutation and polymorphism. RESULTS: All exons of PARKIN gene from the research subjects were successfully amplified. A heterozygous point mutation (Gly284Arg) in exon 7 was found in one pedigree. A polymorphism (Ser167Asn) in exon 4 was found in another pedigree. All the patients had the past history of exposure to environmental poison. CONCLUSION: When acting together with risky environmental factors, the heterozygous mutation Gly284Arg in PARKIN gene may cause AREP. The polymorphism Ser167Asn in PARKIN gene increases the risk of developing Parkinson's disease and may cause AREP when acting together with hydrargyrism.

Age of Onset↗
PubMed2005

[Detection of duplications or deletions of the PMP22 gene using real-time quantitative PCR].

OBJECTIVE: To detect the duplication or deletion of peripheral myelin protein 22(PMP22) gene in Chinese patients with Charcot-Marie-Tooth disease(CMT) or hereditary neuropathy with liability to pressure palsies(HNPP) using real-time quantitative polymerase chain reaction. METHODS: Duplications or deletions of PMP22 gene were detected in 113 CMT cases, 4 HNPP cases and 50 normal controls by using real-time quantitative PCR. RESULTS: Thirty-six of 113 CMT cases had the PMP22 duplication, 4 HNPP cases had the PMP22 deletion. No duplication or deletion was found in 50 normal controls. CONCLUSION: The PMP22 duplication rate in Chinese patients with CMT is 31.9%(36/113). PMP22 deletion is the common cause of HNPP.

Adult↗
PubMed2005

Elevated plasma tissue-type plasminogen activator (t-PA) and soluble thrombomodulin in patients suffering from severe acute respiratory syndrome (SARS) as a possible index for prognosis and treatment strategy.

OBJECTIVE: To detect the presence of endothelial injury in patients with severe acute respiratory syndrome (SARS) via enhanced levels of tissue-type plasminogen activator (t-PA) and soluble thrombomodulin (sTM). METHODS: Case patients were from Xuanwu Hospital (Capital University of Medical Sciences, Beijing, China), and all of them met clinical criteria for SARS. Healthy controls were some of the hospital employees. Endothelial injury bio-markers tPA and sTM were detected by commercial ELISA-methods. RESULTS: Classic plasma markers of endothelial injury, tPA and sTM significantly elevated in SARS patients in comparison to controls [t-PA: 1.48 +/- 0.16 nmol/L versus 0.25 +/- 0.03 nmol/L (P<0.0001), and sTM: 0.26 +/- 0.06 nmol/L versus 0.14 +/- 0.02 nmol/L (P<0.05)]. The only patient who died had extremely high levels of these endothelial injury markers (t-PA: 2.77 nmol/L and sTM: 1.01 nmol/L). The likelihood ratio analysis indicated the excellent discriminating power for SARS at the optimal cut-point of 0.49 nmol/L for tPA and 0.20 nmol/L for sTM, respectively. Significant numerical correlations were found among these endothelial injury markers in SARS patients. The numerical coefficient of correlation Pearson r between t-PA and sTM was 0.5867 (P<0.05). CONCLUSION: Increased plasma concentrations of tPA and sTM in patients with SARS suggest the possibility of endothelial injury. SARS patients might need anticoagulant therapy or fibrinolytic therapy in order to reverse intraalveolar coagulation, microthrombi formation, alveolar and interstitial fibrin deposition. It may not only provide a useful treatment and prognostic index but also allow a further understanding of the pathological condition of the disease.

Adult↗
PubMed2004

Small heat-shock protein 22 mutated in autosomal dominant Charcot-Marie-Tooth disease type 2L.

Charcot-Marie-Tooth (CMT) disease is the most common inherited motor and sensory neuropathy. We have previously described a large Chinese CMT family and assigned the locus underlying the disease (CMT2L; OMIM 608673) to chromosome 12q24. Here, we report a novel c.423G-->T (Lys141Asn) missense mutation of small heat-shock protein 22-kDa protein 8 (encoded by HSPB8), which is also responsible for distal hereditary motor neuropathy type (dHMN) II. No disease-causing mutations have been identified in another 114 CMT families.

Charcot-Marie-Tooth Disease↗
PubMed2004

[Association between genetic polymorphisms of CYP2C19 and CYP2C9 and phenytoin serum concentration].

OBJECTIVE: To investigate the relationship between the genetic polymorphism of cytochrome CYP2C19 and CYP2C9 and the serum concentration of phenytoin (PHT) in patients with epilepsy. METHODS: The peripheral blood samples of 200 patients with epilepsy aged 2 - 68, were collected to undergo PCR. Denaturing high performance liquid chromatography (DHPLC) was used to detect the PCR products so as to examined the 2 common CYP2C19 allele variants and one CYP2C9 allele. The patients were treated with PHT of the dosage of 1.00 - 18.02 mg/kg alone. After 5 half-life periods venous blood was collected before the administration. Fluorescence polarization immunoassay was used to measure the PHT serum concentration standardized by dosage and body weight. RESULTS: The allele frequencies of CYP2C19 * 2, CYP2C19 * 3, and CYP2C9 * 3 were 31%, 8%, and 6% respectively. Thirty-two patients with CYP2C19 and/or CYP2C9 allele variants were classified into 3 groups: extensive metabolizer (EM, n = 11) homozygous for CYP2C19 * 1/* 1 combined with CYP2C9 * 1/* 1 alleles, intermediate metabolizer (IM, n = 14) heterozygous for CYP2C19 * 1/* 2 or CYP2C19 * 1/* 3 alleles, and poor metabolizer (PM, n = 7) with the genotype of CYP2C19 * 2/* 2 or CP2C19 * 2/* 3, or CYP2C19 * 1/* 2 combined with CYP2C9 * 1/* 3. The genotype distribution rates of EM, IM, and PM were 34%, 44%, and 22% respectively. The PHT serum concentration of the PM group was (4.0 +/- 0.9) Css, significantly higher than that of the IM group [(3.0 +/- 0.9) Css, P < 0.05] and that of the EM group [(2.6 +/- 0.8) Css, P < 0.01] without a significant difference between the IM group and EM group. CONCLUSION: Phenytoin is metabolized via CYP2C19 and CYP2C9. The PHT serum concentration of the PM is significantly higher. Genotyping helps predict the clinical response to PHT administration.

Adolescent↗
PubMed2004

ATM activity contributes to the tumor-suppressing functions of p14ARF.

P14/p19ARF (ARF) plays a major role in the activation of p53 by oncogenic signals. The biochemical basis of this has not been fully elucidated. We report here that forced expression of p14ARF enhances phosphorylation of p53 serine 15 (p53S15) in NIH3T3, IMR90 and MCF7 cells. Ectopic expression of the oncogenes c-myc, E2F1 and E1A, all of which activate p53 at least partially via ARF, lead to p53S15 phosphorylation in IMR90 cells. In addition, ectopic expression of p53 also results in p53S15 phosphorylation, suggesting that this is a common event in the ARF-p53 tumor suppression system. Furthermore, p53-, p14ARF-, c-myc- and E2F1-, but not E1A-, induced p53S15 phosphorylation was substantially reduced in AT fibroblasts (GM05823). Downregulation of ATM in MCF7 cells using RNA interference (RNAi) technology significantly attenuated p14ARF- and p53-induced phosphorylation of p53S15. Ectopically expressed ARF in NIH3T3 cells induced ATM nuclear foci and activated ATM kinase. Functionally, ectopic expression of p14ARF and c-myc inhibited the proliferation of IMR90 but not ATM null GM05823 cells, and p14ARF-induced inhibition of MCF7 cell proliferation was significantly attenuated by downregulation of ATM by RNAi. Taken together, these data show a functional role for ATM in ARF-mediated tumor suppression.

3T3 Cells↗
PubMed2004

[Effect of repeated acute hypoxic treatment on the expression of alpha-synuclein in the mouse brain cortex].

An anti-alpha-synuclein (alpha-SYN) monoclonal antibody produced in our laboratory was used to investigate the effect of repeated acute hypoxic treatments on the expression of alpha-SYN in the mouse cerebral cortex. Western blot analysis showed that the expression levels of alpha-SYN in the cortex changed accordingly upon hypoxic exposure times, as that the alpha-synuclein level significantly increased after the first hypoxic exposure and then dropped down to the background level after the fourth hypoxic exposure. Immunohistochemical staining revealed that the alpha-SYN-immunopositive substance was localized not only in the nerve endings, but also within the nuclei of some neurons. The cell density of the neurons with alpha-SYN immunopositive nuclei was increased significantly after the first hypoxic exposure but returned back to control levels after the fourth hypoxic exposure. Our results indicate that both of the alpha-SYN expression level in the brain and the number of the neurons with alpha-SYN positive nuclei are affected by the repeated acute hypoxic treatments and that this modification is hypoxic time-dependent. The mechanism and the physiological significance underlying these changes need to be further investigated.

Animals↗
PubMed2004

Amygdala cyclic adenosine monophosphate response element binding protein phosphorylation in patients with mood disorders: effects of diagnosis, suicide, and drug treatment.

BACKGROUND: Signal transduction abnormalities have been identified in patients with bipolar (BD) and major depressive (MDD) disorders and are targets for lithium and antidepressant drugs. A key downstream target for signal transduction pathways is the transcription factor cyclic adenosine monophosphate (cAMP) response element binding protein (CREB). Therefore, we measured the levels of phosphorylated CREB (pCREB) in the amygdala, a region critical to emotional processing and important in the pathophysiology of both BD and MDD. METHODS: Human postmortem amygdala sections were generously provided by the Stanley Foundation Neuropathology Consortium. Samples consisted of subjects with MDD, BD, schizophrenia (SCZ), and nonpsychiatric-nonneurologic comparison subjects (n = 15 per group). Levels of pCREB were measured by immunohistochemistry, relative to total cell number. RESULTS: There were no differences between diagnostic groups--control subjects and subjects with BD, MDD, or SCZ--but increased numbers of pCREB stained cells were found in several amygdalar nuclei in subjects who had died by suicide. In contrast, patients treated with lithium at the time of death had significantly lower pCREB levels in the same region. CONCLUSIONS: These results suggest that CREB activity may be an important factor in the neurobiology of suicide and the well-documented antisuicidal effect of lithium.

Adult↗
PubMed2004

Stress-induced structural remodeling in hippocampus: prevention by lithium treatment.

Chronic restraint stress, psychosocial stress, as well as systemic or oral administration of the stress-hormone corticosterone induces a morphological reorganization in the rat hippocampus, in which adrenal steroids and excitatory amino acids mediate a reversible remodeling of apical dendrites on CA3 pyramidal cell neurons of the hippocampus. This stress-induced neuronal remodeling is accompanied also by behavioral changes, some of which can be prevented with selective antidepressant and anticonvulsive drug treatments. Lithium is an effective treatment for mood disorders and has neuroprotective effects, which may contribute to its therapeutic properties. Thus, we wanted to determine whether lithium treatment could prevent the effects of chronic stress on CA3 pyramidal cell neuroarchitecture and the associated molecular and behavioral measures. Chronic lithium treatment prevented the stress-induced decrease in dendritic length, as well as the stress-induced increase in glial glutamate transporter 1 (GLT-1) mRNA expression and the phosphorylation of cAMP-response element binding in the hippocampus. Lithium treatment, however, did not prevent stress effects on behavior in the open field or the plus-maze. These data demonstrate that chronic treatment with lithium can protect the hippocampus from potentially deleterious effects of chronic stress on glutamatergic activation, which may be relevant to its therapeutic efficacy in the treatment of major depressive disorder and bipolar disorder.

Animals↗
PubMed2004

Optical amplification of Eu(DBM)3Phen-doped polymer optical fiber.

A preform technique is used to prepare a step-index (SI) polymer optical fiber (POF) doped with Eu(DBM)3Phen. The gain (5.7 dB) at 613 nm of the doped SI POF with Eu3+ content of 4000 in 10(6) wt., 0.4-mm core diameter, and 30-cm fiber length is observed at ambient temperature by end pumping with a YAG at 355 nm. The input signal light is approximately 0.2 W. The results show the possibility of signal gain in a rare-earth-doped POF amplifier and the potential of a polymer doped with rare-earth ions as an active optical device.

Journal Article↗
PubMed2004

Polymorphisms of dopamine receptor and transporter genes and hallucinations in Parkinson's disease.

The authors conducted a case-control study of Parkinson's disease patients with and without visual hallucinations to investigate associations of the polymorphisms of the dopamine receptors D2 32806 C>T (Taq1A), D3 Ser9Gly and Msp1, D5 978T>C and dopamine transporter 3'-UTR 40 bp VNTR with visual hallucinations in Parkinson's disease. No significant differences were found between hallucinators and non-hallucinators in either the genotypic or allelic distributions. Our data suggest that the loci investigated here are not associated with the visual hallucinogenesis in Parkinson's disease.

Aged↗
PubMed2004

Spectra analysis of Nd(DBM)3(TPPO)2 in MMA solution and PMMA matrix.

The absorption spectra of Nd(DBM)3(TPPO)2 (DBM = dibenzoylmethane; TPPO = triphenylphosphine oxide) in methyl methacrylate (MMA) and polymethyl methacrylate (PMMA) were measured. Slater-Condon parameters (F2, F4, F6), Lander parameter (zeta4f), nephelauxetic effect parameters (beta, delta) and Judd-Ofelt parameters (Omega2, Omega4, Omega6) were calculated on the basis of the absorption spectra. Analysis of the relationship between the structure of rare-earth complexes and the nephelauxetic effect, Judd-Ofelt parameter Omega2 was carried out. The radiative properties of Nd(DBM)3(TPPO)2 in PMMA were also predicted according to the Judd-Ofelt theory. The values of the radiative lifetime and the emission cross-section of 4F3/2 --> 4I11/2 fluorescence transition are comparable with those shown by glasses used in the solid-state laser applications.

Chalcones↗
PubMed2004

[Anti-lipid peroxidation effect of Rosa davurica Pall. fruit].

OBJECTIVE: To study the anti-lipid peroxidation action of Rosa davurica Pall. fruit. METHODS: The contents of malondialdehyde (MDA) of the tissue homogenate of the liver, heart, kidney, brain and of the red blood cells induced by hydrogen peroxide in mice were measured. The contents of MDA and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of ischemic myocardium of mice were measured. RESULTS: 0.2 g/L Rosa davurica Pall. fruit could decrease significantly the contents of MDA of the all tissue (P < 0.05). Inhibition rate of 6.7 g/L Rosa davurica Pall. fruit on MDA of the red blood cells induced by hydrogen peroxide was 89.2%. Administration of this extraction successively for six days (ig, 2.0 g x kg(-1) x d(-1)) can significantly reduce the content of MDA (P < 0.01) and augment the activities of SOD and GHS-Px (P < 0.05) in the ischemic myocardium of mice. CONCLUSION: Rosa davurica Pall. fruit can significantly prevent the lipid peroxidation.

Animals↗
PubMed2004

[A study on the relationship between polymorphism of human NAD(P)H: quinone oxidoreductase and Parkinson's disease in Chinese].

OBJECTIVE: To detect the putative association between the polymorphism of human NAD(P)H: quinone oxidoreductase (NQO1) gene and Parkinson's disease(PD). METHODS: Polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) was used to detect the polymorphism of monoamine NQO1 gene cDNA 609 site(C-->T). The frequencies of alleles and genotypes in different PD groups were compared with those of the control group. RESULTS: It was found that the frequencies of TT genotype in the patients with PD and in the controls were 0.226 and 0.118 respectively (P=0.004), i.e., TT genotype increased the risk of PD by 2.186-fold (P=0.005). When the patients with PD were divided into two groups by the age at onset, significant difference in the genotypic frequencies was observed only between late-onset PD group and control group (the frequencies of TT genotype being 0.260 and 0.118, P=0.001) and TT genotype increased the risk of late-onset PD by 2.627-fold(P=0.001). There were no significant differences in frequencies of alleles between different PD groups and control group. CONCLUSION: This study revealed significant differences in genotypic frequencies between PD group and control group. The findings supported the hypothesis about an association between NQO1 gene and PD, suggesting that the age at onset of PD might be related to the putative association, and NQO1 cDNA C609T site be a risk factor for PD.

Adolescent↗
PubMed2004

[New polymorphism (IVS3-20 T-->C) of the parkin gene associated with the early-onset Parkinson's disease in Chinese].

OBJECTIVE: To investigate the association between a new polymorphism (IVS3-20 T>C GenBank accession number: AY463003) in intro 3 of the parkin gene and the risk for Parkinson's disease (PD) in Chinese, particularly the relation between this polymorphism and the age of onset of PD patients. METHODS: PD was diagnosed according to the criteria of Core Assessment Program for Intracerebral Transplantations(CAPIT). All patients and controls were examined by two neurologists and were of the Han ethnic background. Polymerase chain reaction (PCR), denaturing high performance liquid chromatography (DHPLC) and sequencing were used to determine the genotype of each subject. RESULTS: A total of 312 PD patients (including 99 early-onset PD patients and 213 late-onset PD patients) and 236 controls were studied. The C/C homozygote was not found in this study. Chi-square analysis revealed that the frequencies of the C allele and T/C genotype were higher in total PD group but were not statistically different from those of the control group (P=0.6350 and 0.6331, respectively). After being stratified by age of onset, the frequency of T/C genotype was significantly higher (OR=3.52, 95%CI 0.97-13.13) in PD group with an onset age at or below 45 years old (7.07%), compared with that in the control group (2.12%). Similarly, C allele was much higher (OR=3.42, 95%CI 0.96-12.57, P=0.0276) in the early-onset PD group (3.90%) than that in the control group (1.06%). The linear trend analysis showed that both the T/C genotype and C allele increased significantly in the PD group with the increase of the onset age [chi-square(trend of Genotypes)=4.414, P=0.036; chi-square(trend of Alleles)=4.344, P=0.037]. On the other hand, there was no difference in the frequencies of allele and genotype between the late-onset PD patients and controls. CONCLUSION: The above results suggest that the parkin IVS3-20 T>C polymorphism might be a genetic risk factor for early-onset PD in Chinese.

Adult↗