Biomedical subjects

Hui Zhao

Publications and source records attributed to Hui Zhao.

At least 73 records · Page 4Linked to original sources

PubMed2005

Poly[[bis(pyridin-3-ol)manganese(II)]-di-mu-pyridin-3-olato].

In the title complex, [Mn(C5H4NO)2(C5H5NO)2]n or [Mn(mu-3-PyO)2(3-PyOH)2]n (3-PyO- is the pyridin-3-olate anion and 3-PyOH is pyridin-3-ol), the Mn(II) atom lies on an inversion centre and has octahedral geometry, defined by two N atoms and two deprotonated exocyclic O atoms of symmetry-related pyridin-3-olate ligands [Mn-N = 2.3559 (14) A and Mn-O = 2.1703 (11) A], as well as two N atoms of terminal 3-PyOH ligands [Mn-N = 2.3482 (13) A]. The Mn(II) atoms are bridged by the deprotonated pyridin-3-olate anion into a layer structure, generating sheets in the (-101) plane. These sheets are linked by O-H...O hydrogen bonds. There are also pi-pi and C-H...pi interactions in the crystal structure.

Journal Article↗

PubMed2005

Functional characterization of the mitochondrial 12S rRNA C1494T mutation associated with aminoglycoside-induced and non-syndromic hearing loss.

In this study, we report the biochemical characterization of the deafness-associated mitochondrial 12S rRNA C1494T mutation using 27 cybrid cell lines constructed by transferring mitochondria from 9 lymphoblastoid cell lines derived from a Chinese family into human mitochondrial DNA (mtDNA)-less (rho degrees) cells. Six cybrids derived from two asymptomatic members, and nine cybrids derived from three symptomatic members of the Chinese family carrying the C1494T mutation exhibited approximately 38 and 43% decrease in the rate of mitochondrial protein labeling, respectively, compared with twelve cybrids derived from four Chinese control individuals. These defects are apparently a primary contributor to significant reductions in the rate of overall respiratory capacity or the rate of malate/glutamate promoted respiration, or succinate/G3P-promoted respiration, or TMPD/ascorbate-promoted respiration in mutant cybrid cell lines derived from either symptomatic or asymptomatic individuals. Furthermore, the very significant/nearly identical increase in the ratio of doubling times in DMDM medium in the presence/absence of high concentration of paromomycin was observed in symptomatic or asymptomatic cybrid cell lines carrying the C1494T mutation as compared with the average rate in control cell lines. These observations provide the direct biochemical evidences that the C1494T mutation is a pathogenic mtDNA mutation associated with aminoglycoside-induced and non-syndromic hearing loss. In addition, these data provide the first biochemical evidence that nuclear background plays a critical role in the phenotypic manifestation of non-syndromic hearing loss and aminoglycoside toxicity associated with the C1494T mutation.

Cell Growth Processes↗

PubMed2005

Clinical and molecular characterization of a Chinese patient with auditory neuropathy associated with mitochondrial 12S rRNA T1095C mutation.

Mutations in mitochondrial DNA (mtDNA), particularly those in the 12S rRNA gene, have been shown to be associated with sensorineural hearing loss. Recently, a systematic and extended mutation screening of the mitochondrial 12S rRNA gene has been initiated in the large clinical population of the Otology Clinic at the Chinese PLA General Hospital with the aim of identifying mtDNA mutations associated with hearing loss. Here we report the clinical and molecular characterization of a Chinese patient with auditory neuropathy. Sequence analysis of mtDNA in this patient identified a T-to-C transition at position 1095 (T1095C) in the 12S rRNA gene and other nucleotide changes. The T1095C mutation is expected to disrupt an evolutionarily conserved A-to-U base-pair, which is at the highly conserved P-site of 12S rRNA. The T1095C mutation has also been found to be associated with hearing loss in several unrelated families. Among other nucleotide changes, two novel variants: the I175V mutation in the CO2 and the V112M mutation in the ND6 localize at highly evolutionarily conserved residues from different organisms. Furthermore, the absence of mutation in the otoferlin related to auditory neuropathy showed that otoferlin may not be involved in the phenotypic expression of T1095C mutation in this subject. These data suggest that the T1095C mutation may be associated with auditory neuropathy in this subject, and two novel variants I175V and V112M may play a role in the phenotypic expression of the T1095C mutation.

Adult↗

PubMed2005

Chronic idiopathic thrombocytopenic purpura in adult Chinese patients: a retrospective single-centered analysis of 1791 cases.

BACKGROUND: Adult chronic idiopathic thrombocytopenic purpura (ITP) is a common hematologic disease characterized by persistent thrombocytopenia. So far, there were only a few reports on adult Chinese patients with chronic ITP. This study aimed at defining the treatment outcome and prognostic factors for chronic ITP based on a large cohort of Chinese patients followed up for over 25 years at a single center. METHODS: The medical records of 1791 patients aged 14 years or older who were diagnosed as having chronic ITP at our hospital from 1974 to 1999 were retrospectively analyzed. RESULTS: The female-to-male ratio was 2:1, with a median age of 34 years (ranging from 14 to 80 years), median platelet count of 38 x 10(9)/L [range (1-99) x 10(9)/L], and median follow-up of 36 months (range 1-220 months). Steroids were used in 689 patients, among them 209 (30.3%) achieved complete remission (CR). A splenectomy was performed in 124 patients, and response to steroid pre-splenectomy was not available in 14 patients. The CR rate after a splenectomy was lower in steroid nonresponders (29 of 90, 32.2%) than in those who relapsed after successful steroid treatment (12 of 20, 60.0%) (P < 0.05). In comparison with patients negative for antinuclear antibody (ANA), those who were ANA positive had similar responses to steroids, but a significantly shorter remission period after a splenectomy (P < 0.01). CONCLUSIONS: Adult Chinese chronic ITP patients can have long-term remission after steroid therapy and splenectomies. Primary steroid refractoriness is a prognostic factor predicting poor subsequent response to a splenectomy.

Adolescent↗

PubMed2005

Multi-dysfunctional pathophysiology in ITP.

Idiopathic thrombocytopenic purpura (ITP) is an organ-specific autoimmune disorder characterized by a low platelet count and mucocutaneous bleeding. The decrease of platelets is caused by increased autoantibodies against self-antigens, particularly IgG antibodies against GPIIb/IIIa. The production of these autoantibodies by B cells depends on a number of cellular mechanisms that form a network of modulation, with T cells playing a pivotal role in pathophysiology. Delineation of the dysfunction of cellular immunity has recently been attempted. This review will focus on these recent advances applicable to ITP and to highlight how these may translate into novel approaches to treatment in the future. Multi-dysfunction in these networks may include a failure of self-antigen recognition and tolerance, involvement of abnormal cell surface molecules, altered Th1/Th2 cytokine profiles, impaired megakaryocytopoiesis and impaired cell-mediated cytotoxicity. In ITP, multi-step dysfunctions in these networks may take place that finally lead to the occurrence of the disease. Therefore, unveiling these dysfunctions is vital in understanding the pathophysiology of ITP and will finally lead to the development of new therapies to fight the disease.

Cell Communication↗

PubMed2005

Neighboring-nucleotide effects on the mutation patterns of the rice genome.

DNA composition dynamics across genomes of diverse taxonomy is a major subject of genome analyses. DNA composition changes are characteristics of both replication and repair machineries. We investigated 3,611,007 single nucleotide polymorphisms (SNPs) generated by comparing two sequenced rice genomes from distant inbred lines (subspecies), including those from 242,811 introns and 45,462 protein-coding sequences (CDSs). Neighboring-nucleotide effects (NNEs) of these SNPs are diverse, depending on structural content-based classifications (genome-wide, intronic, and CDS) and sequence context-based categories (A/C, A/G, A/T, C/G, C/T, and G/T substitutions) of the analyzed SNPs. Strong and evident NNEs and nucleotide proportion biases surrounding the analyzed SNPs were observed in 1-3 bp sequences on both sides of an SNP. Strong biases were observed around neighboring nucleotides of protein-coding SNPs, which exhibit a periodicity of three in nucleotide content, constrained by a combined effect of codon-related rules and DNA repair mechanisms. Unlike a previous finding in the human genome, we found negative correlation between GC contents of chromosomes and the magnitude of corresponding bias of nucleotide C at -1 site and G at +1 site. These results will further our understanding of the mutation mechanism in rice as well as its evolutionary implications.

Base Composition↗

PubMed2005

A tale of two clades: monkeypox viruses.

Human monkeypox was first recognized outside Africa in 2003 during an outbreak in the USA that was traced to imported monkeypox virus (MPXV)-infected West African rodents. Unlike the smallpox-like disease described in the Democratic Republic of the Congo (DRC; a Congo Basin country), disease in the USA appeared milder. Here, analyses compared clinical, laboratory and epidemiological features of confirmed human monkeypox case-patients, using data from outbreaks in the USA and the Congo Basin, and the results suggested that human disease pathogenicity was associated with the viral strain. Genomic sequencing of USA, Western and Central African MPXV isolates confirmed the existence of two MPXV clades. A comparison of open reading frames between MPXV clades permitted prediction of viral proteins that could cause the observed differences in human pathogenicity between these two clades. Understanding the molecular pathogenesis and clinical and epidemiological properties of MPXV can improve monkeypox prevention and control.

Animals↗

PubMed2005

Distinction of desmoplastic melanoma from non-desmoplastic melanoma by gene expression profiling.

Desmoplastic melanoma (DM) is a variant of melanoma characterized by the presence of amelanotic fusiform melanocytes dispersed in a prominent collagenous stroma. DM behaves differently from conventional non-desmoplastic melanoma (NDM). It has a higher tendency for local recurrence and is less likely to metastasize to regional lymph nodes. In this study, we explored the possibility of distinguishing DM from NDM by gene expression profiling. RNA samples from ten primary cutaneous melanomas of similar depth of invasion were analyzed using the Affymetrix U133A oligonucleotide platform. Four tumors were DM, five were ND, and one tumor showed combined features of desmoplastic and conventional. Hierarchical cluster analysis clearly separated DM from NDM. The expression of a number of melanocyte differentiation genes was decreased in DM compared with NDM, which corresponded to immunohistochemical results. Various genes were upregulated in DM, including neurotrophic factors and genes involved in extracellular matrix production. A novel finding was the high expression of clusterin in DM, which was confirmed by immunohistochemical studies. Our results from gene expression profiling validate the distinction of DM from NDM. They also provide the opportunity to learn more about the biology of DM which had previously not yet been associated with this variant of melanoma.

Biomarkers, Tumor↗

PubMed2005

Organizing the genome: enhancers and insulators.

Enhancers can activate their target genes over large linear distances. Insulators can delimit the influence of an enhancer to an appropriate target. There are a number of intertwined mechanisms by which the regulatory functions of enhancers and insulators might be carried out at the level of the chromatin fiber. Recent evidence suggests that both enhancers and insulators participate in higher-order organization of chromatin in the nucleus and in localization of their regulated sequences to both subnuclear structures and compartments. Novel experimental approaches are helping to reveal the mechanisms underlying nuclear organization of developmentally regulated genes.

Animals↗

PubMed2005

[The effects of bilirubin concentration on laminin and epidermal growth factor expression in lung tissue and type II pneumocytes in smoking rats model].

OBJECTIVE: To explore the effects of bilirubin on expression of laminin (Ln) and epidermal growth factor (EGF) in lung tissue and in type II pneumocytes (ATII) in smoking rats. METHODS: 36 healthy Wistar rats were randomly divided into three groups: a normal group, a smoking-induced emphysema model group (model group), and a bilirubin group (n = 12, for each group). According to XU San-lin method, rats both in the model group and the bilirubin group were exposed to smoke for a total of 6 months. Rats in the bilirubin group were pretreated with indirect bilirubin (20 mg.kg(-1).d(-1)) before exposed to smoke once a day. All animals were sacrificed six months later. ATIIwere isolated, purified and cultured. Ln in ATII culture medium was determined by radioimmunoassay (RIA). We detected Ln in lung tissue with indirect immunofluorescence technique and EGF with immunochemistry. RESULTS: In the model group, Ln content in ATII culture medium and in lung tissue [(5.0 +/- 0.3) mg/ml, 5.67 +/- 0.26] increased significantly compared with those in the normal group [(3.2 +/- 0.5) mg/ml, 2.01 +/- 0.74; P < 0.05, respectively]. In the bilirubin group, the two indexes [(3.9 +/- 0.7) mg/ml, 4.18 +/- 0.63] decreased significantly compared with those in the model group (P < 0.05, respectively), which was higher than the normal group (P < 0.05). Expression of EGF in lung tissue of the model group (0.43 +/- 0.09) increased significantly compared with that of the normal group (0.14 +/- 0.02; P < 0.05). The expression of EGF in the bilirubin group (0.34 +/- 0.03) decreased significantly compared with the model group (P < 0.05), which was higher than that of the normal group. CONCLUSIONS: Bilirubin was shown to be able to promote the reconstruction of extracellular matrix by decreasing the expression of Ln and EGF in lung tissue and in ATII in the development of emphysema.

Animals↗

PubMed2005

[Visualization of regenerated sciatic nerve of rat after injury].

There is close relationship between the morphologic changes of peripheral nerve after injury and its function recovery during regeneration. In our experiment, the sciatic nerve of rats was transected and bridge-connected with silicone tube, and the images of serial slices of different time and different injury parts were taken by micro-photograph system. The volume unit model was applied to rendering the three dimensional (3D) structure of degenerative and regenerative sciatic nerve fiber and its affiliated structure after injury. The 3D images showed that node of Ranvier had not formed and its array was turbulent, both the myelin sheath and the axis-cylinder were thinner, and the collagen fibres had proliferated.

Animals↗

PubMed2005

Retrospective analysis of 472 Chinese children with chronic idiopathic thrombocytopenic purpura: a single center experience.

We retrospectively analyzed the clinical characteristics and management of 472 Chinese children (age 1~14 years) with chronic idiopathic thrombocytopenic purpura (ITP). The distribution of cases by age showed a maximum at 4 years and more patients below 7 years old than between 7 and 14 years old had ITP (337, 71.4% vs. 135, 28.6%). Variable bleeding signs occurred in this series of patients. Steroids therapy was effective for Chinese children with chronic ITP whether as first- or second-line therapy. Traditional Chinese medicine was less effective than steroids.

Adolescent↗

PubMed2005

[Fragment length polymorphism of Wx-B1 gene digested by BamHI and its relation to amylose content of wheat].

There are two types of starch, amylose and amylopectin of flour. Amylose content (AC) is significantly negatively correlated with noodle quality. The waxy gene (Wx) encodes the granule-bound starch synthase (GBSS, EC 3.4.1.11), or Wx protein, is responsible for the synthesis of amylose in wheat. Common wheat is allohexaploid, it has three different Wx proteins: Wx-A1, Wx-B1, and Wx-D1. Consequently, amylose content and pasting properties of starch were influenced by the lack of the Wx-B1 protein, followed by that of Wx-D1, and Wx-A1. Using STS (sequence-tagged sites) primers, the sequences were amplified near the 4th intron region, and fragments amplified were digested by BamHI in 35 wheat cultivars. The results indicate that some fragments can be digested and the other cannot. The fragments digested showed two length polymorphism, and the length is negatively correlated with amylose content. The fragment in many cultivars with amylose content above 20% can be digested by BamHI, while those with amylose content below 20% cannot. All these indices demonstrate that there is variation exists in amplified region of Wx-B1 gene. This can be useful in breeding program to select wheat cultivars with different amylose content, and improve wheat quality.

Amylose↗

PubMed2005

Type 1 and type 2 T-cell profiles in idiopathic thrombocytopenic purpura.

BACKGROUND AND OBJECTIVES: Adult idiopathic thrombocytopenic purpura (ITP) is a chronic acquired organ-specific autoimmune hemorrhagic disease characterized by the production of antibodies against antigens on the membranes of platelet, resulting in enhanced Fc-mediated destruction of the platelets by macrophages in the reticuloendothelial system. Dysfunctional cellular immunity is considered important in the pathophysiology of ITP. The aim of this study was to explore the profile of type1 and type2 T cells in chronic ITP patients. DESIGN AND METHODS: The balance of Th1/Th2 and Tc1/Tc2 was studied by simultaneous analysis of intracellular cytokines of peripheral blood mononuclear cells and splenocytes in short-term cultures activated with PMA/ionomycin as well as mRNA expression of T-bet and GATA-3 in peripheral blood mononuclear cells and splenocytes using real-time polymerase chain reaction. RESULTS: Patients with active disease but not patients in remission had significant higher Th1/Th2 (p<0.01) and Tc1/Tc2 (p<0.01) ratios in peripheral blood (PB) and significant higher Th1/Th2 ratio in splenocytes (p<0.01) than those in the control group. The Tc1/Tc2 ratio in splenocytes in ITP patients was higher than that in control, but did not reach significant difference (p=0.082). GATA-3 mRNA expression in ITP patients was significantly lower both in PB (p<0.01) and in splenocytes (p<0.01) than in corresponding samples from controls while there was no difference in T-bet expression. INTERPRETATION AND CONCLUSIONS: Our data indicate that ITP is a T1 cell (Th1 and Tc1) predominant disease although the precise mechanisms await further functional assay. The T-bet/GATA-3 ratio may provide a surrogate marker of T1/T2 cytokine balance. Shifting the cytokine patterns from T1 to T2 might be a potential immunotherapy for ITP.

Adolescent↗

PubMed2005

[Synthesis, characterization and fluorescence properties of binary and ternary rare earth complexes with N-phenylanthranilic acid and 1, 10-phenanthroline].

Some novel binary and ternary complexes of rare earth (Tb) with N-phenylanthranilic acid and 1,10-phenanthroline were synthesized and their compositions were characterized by elemental analysis. The compositions of the complexes have been confirmed to be TbL3. 4H2O and TbL3 phen.2H20 (L: N-phenylanthranilic acid, phen: 1;10-phenanthroline). The spectroscopic properties of the complexes were discussed. The result shows that the luminescence intensities of binary and ternary complexes were decreased by N-phenylanthranilic acid and 1,10-phenanthroline. It is indicated that the intensity of Tb depends on the structure of ligands. The structure, energy transfer and energy matching were studied, and it is concluded that the structure of complex affects the luminescence properties of the complexes.

Fenamates↗

PubMed2004

Two two-dimensional MnII and NaI coordination polymers constructed by the flexible benzene-1,4-dioxyacetate ligand.

Two new two-dimensional coordination polymers, poly[[[aqua(2,2'-bipyridine-kappa2N,N')manganese(II)]-mu3-p-phenylenebis(oxyacetato)-kappa3O:O':O''] dihydrate], {[Mn(C10H8O6)(C10H8N2)(H2O)].2H2O}n, (I), and poly[[di-mu-aqua-bis[aquasodium(I)]]-mu4-p-phenylenebis(oxyacetato)-kappaO:O',O'':O''',O'''':O'''''], [Na2(C10H8O6)(H2O)4]n, (II), have been synthesized and characterized by X-ray single-crystal diffraction. In (I), there are two 1,4-BDOA2- [p-phenylenebis(oxyacetate) or, more commonly, benzene-1,4-dioxyacetate] ligands, each lying about inversion centres, while in (II), there is one such ligand and it also has crystallographically imposed inversion symmetry. In (I), each Mn(II) atom displays an octahedral MnN2O4 configuration, defined by three carboxyl O atoms of different 1,4-BDOA2- groups, two N atoms of one 2,2'-bipyridine ligand and one water molecule. In (II), each Na(I) atom is octahedrally coordinated by one ether O atom, two carboxyl O atoms of different 1,4-BDOA2- ligands and three water molecules. The metal ions in complexes (I) and (II) are bridged by 1,4-BDOA2- groups into two-dimensional layer structures. Furthermore, three-dimensional supramolecular networks are constructed via hydrogen bonds in (I) and (II), and by additional pi-pi stacking interactions in (I).

Journal Article↗

PubMed2004

Poly[disilver(I)-mu8-1,5-naphthalenedisulfonato].

The title complex, poly[disilver(I)-mu8-1,5-naphthalenedisulfonato-3,4-eta:7,8-eta:kappa6O:O':O'':O''':O'''':O'''''], [Ag2(C10H6O6S2)]n, exists as a three-dimensional framework of Ag(I) atoms connected by eta10,mu8-1,5-naphthalenedisulfonate ligands through both Ag-sulfonate and Ag-eta2-arene interactions. Each Ag(I) atom exhibits a distorted tetrahedral geometry defined by three O atoms of independent sulfonate groups and one C=C bond of the naphthalene group.

Journal Article↗

PubMed2004

catena-Poly[[(pyridin-4-ol-kappaN)silver(I)]-mu-pyridin-4-olato-kappa2N:O].

The title complex, [Ag(C(5)H(4)NO)(C(5)H(5)NO)](n), consists of a polymeric neutral chain involving both a neutral pyridin-4-ol ligand and a deprotonated pyridin-4-olate monoanion. The Ag(I) atom shows a T-shaped coordination geometry, defined by one N atom of the pyridin-4-ol and one O and one N atom of two independent pyridin-4-olate bridges; the N-Ag-N moiety is approximately linear. The polymeric chains are connected via strong O-H...O hydrogen bonds and offset pi-pi interactions into a three-dimensional network.

Journal Article↗