Biomedical subjects

Wenbin Liu

Publications and source records attributed to Wenbin Liu.

7 recordsLinked to original sources

PubMed2025

Streptomyces huangiella sp. nov., an endophytic actinomycete isolated from Pheretima aspergillum, a promising candidate for biological pathogen control.

UNLABELLED: Pheretima aspergillum (E. Perrier) is an annelid of the genus Pheretima in the family Megascolecidae, a species of earthworm, whose dried body (Guang Dilong) is a traditional Chinese animal medicine. A new actinobacterium strain, named HD1123-B1T, was isolated from the gut contents of Pheretima aspergillum caught in the wild in Guangzhou, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain was primarily identified as a member of the genus Streptomyces, sharing more than 98% sequence identity to Streptomyces endocoffeicus CA3R110T (98.80%), Streptomyces coffeae CA1R205T (98.47%), and Streptomyces iranensis HM35T (97.93%). The whole genome size of strain HD1123-B1T was approximately 8.9 Mbp, with 7,464 predicted genes and 71.42 mol% DNA C+G content. Comparative genomic analyses based on digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values revealed that strain HD1123-B1T represents a novel species within the genus Streptomyces. Additionally, 38 biosynthetic gene clusters for secondary metabolites were also predicted in the genome of strain HD1123-B1T. Based on LC-MS/MS analysis, the nigericin biosynthesis gene cluster has been completely characterized. The ethyl acetate crude extract of strain HD1123-B1T exhibited remarkable antibacterial activity against gram-positive bacteria (methicillin-resistant Staphylococcus aureus ATCC 25213, etc) and gram-negative bacteria Ralstonia solanacearum GIM 1.70. Based on these results, HD1123-B1T could be confirmed as an isolate that represents a novel species of the genus Streptomyces, for which the name Streptomyces huangiella sp. nov. is proposed. IMPORTANCE: As the largest genus of the phylum Actinomycetes, Streptomyces is a kind of microbial resources with great practical and economic value. Due to their unique physiological properties and metabolic capacity, Streptomyces have become an important source of bioactive compounds in the world and play an indispensable role in medical and industrial fields. With the advancement of molecular biology and genomics, researchers can more deeply explore the metabolic potential of Actinomycetes, discovering and developing new biologically active compounds. These new compounds may possess various biological activities, such as antibacterial, antiviral, antifungal, and antiparasitic properties, further promoting the development of medicine and related industries. Based on genomic analysis and antibacterial activity, the strain HD1123-B1T was indicated to be a promising candidate for biological pathogen control.

Streptomyces↗

PubMed2003

Development of a comparative genomic hybridization microarray and demonstration of its utility with 25 well-characterized 1p36 deletions.

Chromosomal abnormalities, such as deletions and duplications, are characterized by specific and often complex phenotypes resulting from an imbalance in normal gene dosage. However, routine chromosome banding is not sensitive enough to detect subtle chromosome aberrations (<5-10 Mb). Array-based comparative genomic hybridization (array CGH) is a powerful new technology capable of identifying chromosomal imbalance at a high resolution by co-hybridizing differentially labeled test and control DNAs to a microarray of genomic clones. We used a previously assembled contig of large-insert clones that span 10.5 Mb of the most distal region of 1p36 to design a microarray. The array includes 97 clones from 1p36, 41 clones from the subtelomeric regions of all human chromosomes, and three clones from each of the X and Y chromosomes. We used this microarray to study 25 subjects with well-characterized deletions of 1p36. All array CGH results agree with the deletion sizes and locations of the breakpoints in these subjects as determined previously by FISH and microsatellite analyses. Terminal deletions, interstitial deletions, derivative chromosomes and complex rearrangements were also identified. We anticipate that array CGH will change the diagnostic approach to many congenital and acquired genetic diseases such as mental retardation, birth defects and cancer.

Chromosome Aberrations↗

PubMed2003

The effects of polyethylene glycol on gene expression of developing white spruce somatic embryos.

Somatic embryogenic cultures of white spruce (Picea glauca) represent a valuable system to study molecular mechanisms regulating embryo development because many embryos of defined developmental stages can be generated. The inclusion of polyethylene glycol (PEG) in the maturation medium can improve the number and quality of embryos produced. To learn more about the mechanism of action of PEG, we analyzed transcript profiles of stage-specific embryos matured without (control) or with (PEG treated) PEG. RNA extracted from maturing spruce embryos was analyzed on DNA microarrays containing 2,178 cDNAs from loblolly pine (Pinus taeda). The efficiency of heterologous hybridization between spruce and pine species on microarrays has been documented previously (L. van Zyl, S. von Arnold, P. Bozhkov, Y. Chen, U. Egertsdotter, J. MacKay, R. Sederoff, J. Shen, L. Zelena, D. Clapham [2002] Comp Funct Genomics 3: 306-318). Several pine genes, including the apparent homologs to the Arabidopsis genes ZWILLE, FIDDLEHEAD, FUSCA, and SCARECROW, increased in expression after PEG treatments. These genes are known to be involved in the formation of the embryo body plan and in the control of the shoot and root apical meristems. The increased transcript levels of these genes in immature PEG-treated embryos suggest that PEG may improve the quality of spruce somatic embryos by promoting normal differentiation of the embryonic shoot and root. Changes in the transcript levels of many genes involved in sucrose catabolism and nitrogen assimilation and utilization were also observed between control and PEG-treated embryos.

Arabidopsis Proteins↗

PubMed2002

[Effects of antisense transforming growth factor beta receptor-I expressing plasmid on pig serum-induced rat liver fibrosis].

OBJECTIVE: To observe the effects of antisense transforming growth factor beta receptor-I (TbetaRI) expressing plasmid on rat liver fibrosis. METHODS: RT-nested-PCR and gene recombinant techniques were used to construct the rat antisense TbetaRI recombinant plasmid which can be expressed in eucaryotic cells. The recombinant plasmid and blanx vector (pcDNA3) were encapsulated by glycosyl-poly-L-lysine and then transducted into rats of pig serum-induced liver fibrosis model respectively. Expression of exogenous transfected plasmid was assessed by Northern blot, RT-PCR, Western blot and immunohistochemistry. Serum TGF-beta(1) was determined by ELISA. The content of hepatic hydroxyproline was tested. Immunohistochemistry was used to test type I and III collagen. VG staining was used for pathological study. RESULTS: The exogenous antisense TbetaRI could be expressed in vivo, and could block the mRNA and protein expression of TbetaRI in the fibrotic liver induced by pig serum. Its expression also reduced the level of TGF-beta(1) (P < 0.05) and decreased the the contents of hepatic hydroxyproline and the deposition of collagens type I and type III (P < 0.01). And its expression also improved the pathologic classification of liver fibrosis models (P < 0.01). CONCLUSIONS: The results demonstrate that the antisense TbetaRI recombinant plasmid has certain extern reverse effect on liver fibrosis and make it as a possible candidate for use in future gene therapy.

Activin Receptors, Type I↗

PubMed2002

[Intraocular lens implantation and coreoplasty for congenital cataract after optical iridectomy].

OBJECTIVE: To explore the therapeutic method for congenital perinuclear cataract after optical iridectomy. METHODS: Twelve cases (24 eyes) with congenital perinuclear cataract after optical iridectomy were selected. After extracapsular cataract extraction (ECCE) and intraocular lens (IOL) implantation, the sides of the iridectomy were sutured to complete the coreoplasty. RESULT: No patient complained of photophobia and monocular diplopia postoperatively. Every one got a nearly round pupil with light reaction and a corrected visual acuity >/= 0.5. CONCLUSION: The combination of ECCE, IOL implantation and coreoplasty is a good therapeutic method for congenital perinuclear cataract after optical iridectomy.

Adolescent↗

PubMed2002

[Clinical and pathological characteristics of primary biliary cirrhosis].

OBJECTIVE: In order to improve the cognition and early diagnosis of primary biliary cirrhosis (PBC), we investigated clinical and pathological characteristics of PBC. METHODS: Clinical data of 37 PBC patients together with pathological findings of 20 PBC patients were reviewed. RESULTS: Among the 37 patients, 35 were women and the mean age at diagnosis was (53.4 8.9) years. The most frequent clinical presentations were jaundice (70.3%), fatigue (70.3%), and pruritus (56.8%). Serum glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) levels were markedly elevated in all patients (P50 was 467.50 U/L and 424.00 U/L, respectively). Among the 37 cases, 35 (94.6%) had total bile acids elevation, 32 (86.5%) had serum cholesterol elevation and 32 (86.5%) serum IgM elevation, 34 (91.9%) were positive for anti-mitochondrial antibody (AMA) and/or AMA-M2. Liver biopsy in 20 PBC patients mainly found: fibrosis in 17 cases (85%), interlobular bile duct lesions in 13 (65%), lobular mononuclear inflammation in 13 (65%), lymphocytic hepatocellular piecemeal necrosis in 10 (50%), and bile pigment accumulation in 9 (45%). The results of nonparametric test showed that GGT was related with pathological stage (P=0.002) and interlobular bile duct lesions (P=0.01). CONCLUSIONS: PBC is mostly found in middle-aged women. Accurate and prompt diagnosis of PBC should be based on the clinical presentation, biochemical and immunological indexes, and hepatic pathological changes. The level of GGT may partly reflect the severity of the histological lesions

Bile Acids and Salts↗

PubMedDate not supplied

A DNA algorithm for the graph coloring problem.

A DNA algorithm based on surfaces for the graph coloring problem is presented. First the whole combinatorial color assignments to the vertices of a graph are synthesized and immobilized on a surface; then a vertex is legally colored while those adjacent to it with illegal colors are deleted; and the cycle is repeated until finally the correct color assignments to the graph are reached. Compared with the other DNA algorithms, our algorithm is easy to implement and error-resistant.

Algorithms↗