Biomedical subjects

Chen Shao

Publications and source records attributed to Chen Shao.

10 recordsLinked to original sources

PubMed2006

Studies on the interactions of Ti-containing polyoxometalates (POMs) with SARS-CoV 3CLpro by molecular modeling.

Ti-containing alpha-Keggin polyoxometalates (POMs) have been proved with properties of both anti-tumor and anti-HIV (human immunodeficiency virus). The potential anti-SARS (severe acute respiratory syndrome) activity of the POMs [alpha-PTi(2)W(10)O(40)](7-) isomers was investigated in this paper by molecular modeling method. The SARS 3c like protease, namely the SARS 3CL(pro) is the key function protease for virus replication as well as transcription and thus can be taken as one of the key targets for anti-SARS drug design. Affinity/Insight II was used to explore possible binding locations for POMs/3CL(pro) interaction. Charges in the POMs were obtained from density-functional theory (DFT) method. The results show that POMs bind with 3CL(pro) in the active site region with high affinity; POMs are more prone to bind with 3CL(pro) than with some organic compounds; for the POMs/3CL(pro)complex, the OTi(2) in POMs is the vital element for electrostatic interaction, and the electrostatic binding energy is strong enough to keep the complex stable.

Coronavirus 3C Proteases↗

PubMed2006

An integrated machine learning system to computationally screen protein databases for protein binding peptide ligands.

A fairly large set of protein interactions is mediated by families of peptide binding domains, such as Src homology 2 (SH2), SH3, PDZ, major histocompatibility complex, etc. To identify their ligands by experimental screening is not only labor-intensive but almost futile in screening low abundance species due to the suppression by high abundance species. An ideal way of studying protein-protein interactions is to use high throughput computational approaches to screen protein sequence databases to direct the validating experiments toward the most promising peptides. Predictors with only good cross-validation were not good enough to screen protein databases. In the current study we built integrated machine learning systems using three novel coding methods and screened the Swiss-Prot and GenBank protein databases for potential ligands of 10 SH3 and three PDZ domains. A large fraction of predictions has already been experimentally confirmed by other independent research groups, indicating a satisfying generalization capability for future applications in identifying protein interactions.

Amino Acid Motifs↗

PubMed2006

A new investigation of the marine ciliate, Trachelostyla pediculiformis (Cohn, 1866) Borror, 1972 (Ciliophora, Hypotrichida), with establishment of a new genus, Spirotrachelostyla nov. gen.

The morphology and infraciliature of the type species of the ciliate genus Trachelostyla, T. pediculiformis (Cohn, 1866) Borror, 1972, collected from the Bohai Sea near Tianjin, north China, were investigated using live observation and protargol impregnation. The Chinese population corresponds well with the original description, as follows: size about 80-150 x 20-30 microm in vivo; body dorsoventrally flattened and non-spiral; outline elongate, with anterior region conspicuously narrowed while posterior not; on average 14 macronuclear nodules, two micronuclei and 42 adoral membranelles; 16-24 cirri in left and 21-31 in right marginal row. In total 18 frontoventral-transverse cirri: constantly 11 cirri in frontal area and two ventral ones together with five enlarged transverse cirri (TC). Three inconspicuous caudal cirri (CC); six dorsal kineties with prominent cilia. The literature on T. pediculiformis is critically reviewed, showing that the descriptions so far do not agree very well. To clarify the taxonomic status of this species, the population from the Chinese coast of the Bohai Sea is designated as a neotype. The small subunit rRNA gene was sequenced for the neotype and the molecular phylogenetic tree basically supports the establishment of the family Trachelostylidae Small & Lynn, 1985. Based on the data obtained, the genus Trachelostyla Borror, 1972 is redefined thus: dorsoventrally flattened trachelostylids, body non-spirally twisted and elongate, with peristomal region conspicuously narrowed; ciliature generally in 11:2:5:3 pattern, i.e. 11 cirri in frontal region, two ventral cirri located anterior to five TC, three CC present; one left and one right row of marginal cirri not confluent posteriorly. A new genus Spirotrachelostyla nov. gen. is proposed to include the taxa which were previously assigned to Trachelostyla but characterized by spirally twisted, spindle-like body shape and a variable number of cirri in the peristomal area. Three new combinations are suggested: Spirotrachelostyla spiralis (Dragesco & Dragesco-Kernéis, 1986) nov. comb. [basionym: Trachelostyla spiralis Dragesco & Dragesco-Kernéis, 1986], S. tani (Hu & Song, 2002) nov. comb. [basionym: T. tani Hu & Song, 2002] and S. simplex (Kahl, 1932) nov. comb. [basionym: Stichotricha simplex Kahl, 1932].

Animals↗

PubMed2005

Cell division and morphology of the marine ciliate, Condylostoma spatiosum Ozaki and Yagiu (Ciliophora, Heterotrichida) based on a Chinese population.

The morphology and morphogenesis of the large marine heterotrichous ciliate, Condylostoma spatiosum Ozaki & Yagiu in Yagiu, 1944, isolated from Jiaozhou Bay off Qingdao (Tsingtao), China, were investigated using live observation and protargol impregnation. A detailed redescription is given since no infraciliature data about this "well-studied" species are available. It is characterized by: size in vivo 400-700 x 90-140 microm; buccal field about 1/3 of body length; adoral zone composed of 130 membranelles on average; invariably two prominent membrane-like frontal cirri, which are parallel to each other; about 58 somatic kineties; macronucleus composed of 13-22 fragments. Morphogenesis proceeds basically as described in a previous report and can be summarized as follows: (1) the parental adoral zone of membranelles is partly dedifferentiated and then renewed in the posterior portion; (2) in the proter, both the frontal cirri and the paroral membrane are newly formed by anlagen derived from the disaggregated old structures; (3) in the opisthe the anlagen of the paroral membrane and the frontal cirri develop from the right margin of the oral primordium; (4) two frontal cirri are formed one after the other by the frontal cirral anlage; (5) during morphogenesis, no recognizable duplication of basal bodies takes place in somatic kineties; and (6) the macronucleus divides after prior fusion. One reorganizer was observed showing that the basic process of reorganization is obviously similar to that in division.

Animals↗

PubMed2005

Change of the cell cycle after flutamide treatment in prostate cancer cells and its molecular mechanism.

AIM: To explore the effect of androgen receptor (AR) on the expression of the cell cycle-related genes, such as CDKN1A and BTG1, in prostate cancer cell line LNCaP. METHODS: After AR antagonist flutamide treatment and confirmation of its effect by phase contrast microscope and flow cytometry, the differential expression of the cell cycle-related genes was analyzed by a cDNA microarray. The flutamide treated cells were set as the experimental group and the LNCaP cells as the control. We labeled cDNA probes of the experimental group and control group with Cy5 and Cy3 dyes, respectively, through reverse transcription. Then we hybridized the cDNA probes with cDNA microarrays, which contained 8 126 unique human cDNA sequences and the chip was scanned to get the fluorescent values of Cy5 and Cy3 on each spot. After primary analysis, reverse transcription polymerase chain reaction (RT-PCR) tests were carried out to confirm the results of the chips. RESULTS: After AR antagonist flutamide treatment, three hundred and twenty-six genes (3.93%) expressed differentially, 97 down-regulated and 219 up-regulated. Among them, eight up-regulated genes might be cell cycle-related, namely CDC10, NRAS, BTG1, Wee1, CLK3, DKFZP564A122, CDKN1A and BTG2. The CDKN1A and BTG1 gene mRNA expression was confirmed to be higher in the experimental group by RT-PCR, while p53 mRNA expression had no significant changes. CONCLUSION: Flutamide treatment might up-regulate CDKN1A and BTG1 expression in prostate cancer cells. The protein expressions of CDKN1A and BTG1 play an important role in inhibiting the proliferation of cancer cells. CDKN1A has a great impact on the cell cycle of prostate cancer cells and may play a role in the cancer cells in a p53-independent pathway. The prostate cancer cells might affect the cell cycle-related genes by activating AR and thus break the cell cycle control.

Androgen Receptor Antagonists↗

PubMed2004

Expression and significance of Rap1A in testes of azoospermic subjects.

AIM: To evaluate the Rap1A mRNA expression and its significance in the testes of normal and azoospermic subjects. METHODS: A cDNA microarray that contained Rap1A and some other genes such as RBM, EIF1AY was used to identify the differential gene expression profiles between the normal and azoospermic testes. cDNA probes were prepared by labeling mRNA from azoospermic and normal testicular tissues through reverse transcription with Cy5-dUTP and Cy3-dUTP, respectively. The mixed cDNA probes were then hybridized with cDNA microarray (each containing 4096 unique human cDNA sequences). The fluorescent signals were scanned and the values of Cy5-dUTP and Cy3-dUTP on each spot were analyzed and calculated. In situ hybridization was employed to detect the expression of Rap1A in the testes of 10 fertile and 39 azoospermic subjects. RESULTS: One hundred and twenty-eight differentially expressed genes were found to be possibly related to azoospermia, of which 56 were up-regulated and 72, down-regulated genes. The mRNA expression of Rap1A in the spermatogenic cells of azoospermic was stronger than that in those of the fertile testes. CONCLUSION: Rap1A may play certain roles in the development of azoospermia.

Adult↗

PubMed2003

[A study of aspermia-related genes by genchips and analysis of the RAP1A gene].

OBJECTIVE: To study the differential gene expression profiles between the normal and aspermia human testes by genechips. METHODS: Probes were prepared from mRNA extracted from both normal and aspermia testes and employed on Biostar H-40s genechips to detect the differential gene expression profiles. A distinctly up-regulated gene RAP1A was analyzed by bibliogrphic retrieval. RESULTS: Six hundred and twenty-three differential expressed genes were found, among which the distinctly up-regulated gene RAP1A was closely related to human sperm regulation. CONCLUSIONS: Screening the differential gene expression profiles between the normal and aspermia human testes by genechips can be used in the study of aspermia-related genes.

Adult↗

PubMed2003

[Protective effect of nitric oxide synthase inhibitor (L-NAME) on germ cell apoptosis in experimentally cryptorchid rats].

OBJECTIVE: To explore the protective effect of nitric oxide synthase inhibitor (L-NAME) on the germ cell apoptosis in the rat cryptorchid. METHODS: Immature rats (22 day-old Sprague Dawley) were subjected to unilateral cryptorchid. Thirty rats were divided into three groups: sham operation group (testes still in the scrotum after operation); operation group; operation + L-NAME group(given L-NAME 10 mg/kg after operation, dip). Seven days after operation germ cell apoptosis was detected by terminal-deoxynucleotidyl transferase mediated-dUTP nick end labeling(TUNEL). Biochemical parameters (NO, NOS) were evaluated with spectrophotometric determination. RESULTS: At the 7th day after the operation, compared with the control, the number of apoptotic germ cells in the cryptorchid testis was increased significantly, but the testis weight was decreased predominantly(P < 0.01). The levels of NO and NOS in the cryptorchid were significantly higher than the control. CONCLUSIONS: The levels of NO and NOS might be involved in the germ cell apoptosis in the cryptorchid; L-NAME could protect the germ cell from apoptosis in experimentally cryptorchid rats by reducing the activity of NOS and reducing the level of NO in the testis.

Animals↗

PubMed2003

[The biological characteristics of beta glucuronidase cDNA transfected renal cancer cell line GRC 1/betaG].

AIM: To establish a renal carcinoma cell line which can highly express beta-glucuronidase(betaG), and to observe the biological characteristics of the transfected cells. METHODS: Recombinant eukaryotic expression vector pcDNA3.1-betaG was constructed. It was transfected into renal cancer cells GRC-1 via liposome. The transcription and expression of betaG gene were detected by dot blot and Western blot. The biological characteristics of the betaG gene transfected cells was observed under light microscope, transmission electron microscope and flow cytometry. RESULTS: Dot blot and Western blot detection confirmed that the betaG gene had been stably integrated into the genomic DNA of the GRC-1 cells and was highly expressed. Transmission electron microscope observation showed that the lysosomes and endoplasmic reticulum were abundant, the number of microvili and process was significantly increased in the transfected cells, but growth condition and cell cycle of GRC-1 cells had no notable difference before and after transfection. CONCLUSION: A renal carcinoma cell line that can highly express betaG gene was established, which lays the foundation for further study on gene therapy.

Animals↗

PubMedDate not supplied

Morphogenesis of the marine ciliate, Pseudoamphisiella alveolata (Kahl, 1932) Song & Warren, 2000 (Ciliophora, Stichotrichia, Urostylida) during binary fission.

Morphogenesis during the binary fission of the stichotrich ciliate Pseudoamphisiella alveolata, isolated from Jiaozhou Bay near Qingdao, China, was investigated using protargol silver impregnation. The process is characterized as follows: (1) in the proter, only the posterior part of the parental adoral zone of membranelles is renewed, where the membranelles dedifferentiate and then rebuild the UM-anlage and the missing membranelles, (2) the oral primordium in the opisthe and the FVT-anlagen in both dividers are formed de novo on the cell surface, (3) an "extra" anlage, which is generated on the right of the right marginal anlage, develops into three or four "extra" marginal cirri that connect the caudal cirri with the marginal rows, (4) the right marginal anlage is formed within the old structure, (5) the FVT-cirri develop in a primary mode, and (6) unlike most stichotrichs, the right marginal anlagen in both dividers generate closely together. As an additional contribution, the diversity of morphogenetic patterns within the genus Pseudoamphisiella is discussed. Based on both morphogenetic and SS rRNA gene sequencing data, the systematic position of the genus Pseudoamphisiella as well as the family Pseudoamphisiellidae Song et al. 1997 is briefly analyzed. The results indicate that they should very possibly represent a higher evolved group in the order Urostylida.

Animals↗