Biomedical subjects

Ping Zhao

Publications and source records attributed to Ping Zhao.

At least 73 records · Page 4Linked to original sources

PubMed2005

Immune responses against SARS-coronavirus nucleocapsid protein induced by DNA vaccine.

The nucleocapsid (N) protein of SARS-coronavirus (SARS-CoV) is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DH5alpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobulins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity (DTH) and CD8(+) CTL responses to N protein. The study shows that N protein of SARS-CoV not only is an important B cell immunogen, but also can elicit broad-based cellular immune responses. The results indicate that the N protein may be of potential value in vaccine development for specific prophylaxis and treatment against SARS.

Animals↗

PubMed2005

Charge couple device-based system for 3-dimensional real time positioning on the assessment of segmental range of motion of lumbar spine.

OBJECTIVE: To observe the tested results of the segmental range of motion (ROM) of lumbar spine by charge couple device (CCD)-based system for 3-dimensional real-time positioning (CCD system), and to analyze its clinical significance. METHODS: Seven patients with lumbar joint dysfunction and 8 healthy subjects were tested twice by the CCD-based system with an interval of 10 min. RESULTS: The ROM of the patients was obviously lesser than that of the healthy subjects. The measuring data of segmental ROM of lumbar spine by CCD system is correlated significantly to the same data checked later on the same subjects in every direction of the movements. The differences between two checks are usually less than 1 degree. CONCLUSION: Specially designed CCD based system for 3-dimensional real-time positioning could objectively reflect the segmental ROM of lumbar spine. The system would be of great clinical significance in the assessment of the biomechanical dysfunction of lumbar spine and the effect of the treatment applied.

Computer Systems↗

PubMed2005

Genetic polymorphisms in methylenetetrahydrofolate reductase and thymidylate synthase and risk of pancreatic cancer.

BACKGROUND & AIMS: Human pancreatic cancer might be associated with folate deficiency and impaired metabolism. We tested this hypothesis by examining the contribution of functional polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TS) to risk of cancer. METHODS: DNA from 163 pancreatic cancer patients and 337 control subjects was genotyped for MTHFR (677C > T and 1298A > C) and TS (5'-untranslated region tandem repeat and G/C). Association with risk of pancreatic cancer was estimated by logistic regression. All statistical tests were two-sided. RESULTS: We observed an increased risk of pancreatic cancer associated with the MTHFR 677CT (odds ratio [OR], 2.60; 95% confidence interval [CI], 1.61-4.29; P = .0005) or 677TT (OR, 5.12; 95% CI, 2.94-9.10; P < .0001) genotype compared with the MTHFR CC genotype. An increased risk of pancreatic cancer was also associated with the TS 3Rc/3Rc genotype (OR, 2.19, 95% CI, 1.13-4.31; P = .022) compared with the TS 3Rg/3Rg genotype. Joint effect between MTHFR C677T polymorphism and smoking or drinking increased risk of pancreatic cancer in a super-multiplicative manner. The ORs for smoking, the polymorphism, and both factors combined were 0.70 (95% CI, 0.30-1.63), 2.17 (95% CI, 1.17-4.21), and 3.10 (95% CI, 1.54-6.51), respectively. This joint effect was much stronger in heavy smokers (OR, 6.69; 95% CI, 3.39-13.63; P < .0001). The ORs for drinking, the polymorphism, and both factors combined were 0.98 (95% CI, 0.40-2.30), 2.81 (95% CI, 1.65-4.98), and 4.39 (95% CI, 2.25-8.78), respectively. CONCLUSION: The MTHFR and TS polymorphisms are genetic determinants for developing pancreatic cancer.

Adult↗

PubMed2005

Identification and expression pattern of Bmlark, a homolog of the Drosophila gene lark in Bombyx mori.

Two Bombyx mori isoforms of the gene lark, which is shown to play an important role in Drosophila circadian rhythms, were identified and named Bmlark-PA and Bmlark-PB, respectively. Bmlark-PA consists of 5 exons and encodes a protein of 343 amino acid residues which contains 3 functional domains: two RRM (RNA recognization motif) domains and an RTZF (retroviral-type zinc finger) and shares 72% identity with the Drosophila gene lark at the amino acid level. Bmlark-PB lacks the sequence between 118 and 791 nt of Bmlark-PA and codes for a protein of 68 amino acid residues, which contains no distinct functional domains. Alignments of the cDNAs of Bmlark to the genomic draft sequence of B. mori showed that the gene Bmlark had a single copy in the genome, suggesting that an alternative splicing mechanism occurs in the gene Bmlark. RT-PCR analysis indicated that Bmlark-PA was expressed only in late pupae and adult but Bmlark-PB was broadly expressed in many tissues and throughout the developmental stages from embryo to adult.

Alternative Splicing↗

PubMed2005

Molecular evolution of human influenza A/H3N2 virus in Asia and Europe from 2001 to 2003.

Hemagglutinin sequences of 146 human influenza A/H3N2 strains identified in respiratory specimens from Asia and Europe during the 2001-2003 influenza seasons were analyzed by DNA sequencing. Our results suggest that four amino acid substitutions, L25I, H75Q, H155T, and Q156H, led to the antigenic conversion of the previously predominant A/Panama/2007/99-like strains to the more recent A/Fujian/411/2002-like strains.

Amino Acid Substitution↗

PubMed2005

Detection and characterization of new influenza B virus variants in 2002.

One-hundred five influenza B-positive specimens obtained from southeast Asia in 2002 were categorized on the basis of DNA sequencing of HA1 gene as well as real-time PCR analysis of the NA gene. Phylogenetic analysis of the HA1 gene sequences showed that the majority of the viruses (96.2%) belonged to the B/Victoria/2/87 lineage, while a smaller percentage of the viruses (3.8%) belonged to the B/Yamagata/16/88 lineage. The B/Yamagata/16/88 viruses displayed significant antigenic drift in the deduced amino acid sequences of the HA1 protein, and the B/Victoria/2/87-like viruses consisted of B/Hong Kong/1351/02-like (72.3%) and B/Hong Kong/330/01-like (27.7%) viruses. The B/Hong Kong/1351/02-like viruses were reassortants with the HA gene belonging to the B/Victoria/2/87 lineage and the NA gene belonging to the B/Yamagata/16/88 lineage, whereas both the HA and NA genes of B/Hong Kong/330/01 virus belonged to the B/Victoria/2/87 lineage. In this study, however, all the B/Hong Kong/330/01-like isolates exhibited the B/Yamagata/16/88-like NA gene, which likely resulted from reassortment of B/Hong Kong/330/01 and B/Hong Kong/1351/02 viruses during coinfection. Additional molecular characterization of the six internal genes showed that the M, NS, PA, and PB2 genes of the new variants were B/Hong Kong/1351/02 in origin, whereas the NP and PA genes retained the B/Hong Kong/330/01 origin. Interestingly, these new variants all appeared late in the year 2002. These results support the notion that influenza B viruses continued to evolve through antigenic drift and shift.

Base Sequence↗

PubMed2005

Small interfering RNA-mediated inhibition of hepatitis G virus gene expression in human hepatoma cell Huh-7.

The RNA interference (RNAi) phenomenon is a recently observed process in which the introduction of a double-stranded, small interfering RNA (siRNA) into a cell causes the specific degradation of a homologous single-stranded RNA. It represents an exciting new technology that could have therapeutic applications for the treatment of viral infections. Since hepatitis G virus (HGV) genome is a positive-sense single-stranded RNA, the replication of HGV does not lead to an integrated DNA genome, suggesting a particularly attractive target for RNAi study that could eliminate viral RNA from infected cells. The eukaryotic expression vector pVAX.EH containing the cDNA sequences of the entire HGV structural genes and hygromycin resistance gene downstream from the encephalomyocarditis virus (ECMV) internal ribosome entry site (IRES) was constructed and transfected into human hepatoma cell Huh-7. The modified cleavage products of the structural proteins of HGV expressed in hygromycin-resistant cell line Huh-7-EH were confirmed by RT-PCR and Western blot methods. Two specific HGV E2 siRNAs (1-E2 siRNA, 2-E2 siRNA) synthesized with T7 RNA polymerase by transcription in vitro were transfected into the Huh-7-EH cells. With the analyses of Western blot and the formation of hygromycin-resistant colonies, the inhibitions of expression of HGV structural protein by two HGV E2 siRNAs were detected and found lasting at least one week. The inhibition of 2-E2 siRNA was stronger and only 1% of the cells treated with 2-E2 siRNA formed hygromycin-resistant colonies. These results support that specific HGV 2-E2 siRNAs mediate the degradation of mRNA spanning from HGV structural gene cDNA to hygromycin resistance gene in a majority of cells. In conclusion, the Huh-7-EH cells expressing HGV structural proteins stably can be used as a cell model for studying the replication of HGV and RNAi and the enlargement of RNAi may exist, in mammalian cells.

Antiviral Agents↗

PubMed2005

Construction of human naïve Fab library and characterization of anti-met Fab fragment generated from the library.

Inappropriate expression of the receptor tyrosine kinase Met and its ligand hepatocyte growth factor (HGF)/scatter factor (SF) is usually associated with an aggressive solid tumor phenotype (angiogenesis, invasiveness, and metastasis) and poor clinical prognosis. We report here the design and construction of a large, human naïve antigen-binding fragment (Fab) phage-display library with a diversity of 2.0 x 109, which allows rapid isolation of antigen-specific human antibody fragments. A Fab fragment specifically against Met (designated hFab-Met-1) was successively selected from this library by using biopanning on Met-transfected cell line S114. The specificity of hFab-Met-1 was characterized by immunoprecipitation, Western blotting, and flow cytometry. The results demonstrate that hFab-Met-1 reacts with the extracellular domain of Met in its native conformation. Moreover, functional analysis by Madine-Darby canine kidney cell scattering and urokinase-type plasminogen activator assays demonstrated that hFab-Met-1 is not an agonist to HGF/Met signaling compared with a murine intact monoclonal antibody (MAb) Met5. To confirm that hFab-Met-1 interacts with Met-expressing tumors in vivo, I-125-labeled hFab-Met-1 was nuclear-imaged in a mouse xenograft of Met- and HGF/SF-expressing human leiomyosarcoma. Total body scintigrams were obtained between 1 and 48 h postinjection (PI). Tumor-associated activity was imaged as early as 1 h PI, and remained visible in some animals as late as 24 h PI. As expected, activity was highest in the kidneys in early images, whereas thyroid activity became predominant in later images. In conclusion, hFab-Met-1 interacts with Met both in vitro and in vivo, and is a promising candidate for clinical diagnosis and therapeutics.

Animals↗

PubMed2005

[Scientometrics and bibliometrics of chronotherapy].

In order to retrieve Chinese and foreign articles of chronotherapy, we searched Chinese databases of CBM, CMCC and foreign series databases in OVID and hence revealed and assessed the current status, research trend and level of chronotherapy in China and in foreign countries by means of scientometric and bibliometric parameters. ProCite5 software and handsearching were used to manage, check and statistically analyze the searched papers so as to find the parameters which included distributions of databases, years, authors, periodicals, subject headings, organizations and nations. 91 Chinese papers were identified which were distributed in 73 kinds of journals and in subject headings, e.g., Traditional Chinese medicine, cardiovascular diseases, neoplasms, asthma, peptic ulcer, diabetes mellitus, general review of chronotherapy, etc. 480 foreign articles were identified which mainly came from EMBASE and MEDLINE and were distributed in 285 types of journals and 35 nations and regions. There were 14 journals which recorded five or more articles. 12 researchers published more than five articles. Paul Brousse Hospital, University of Texas, University of Connecticut School of Medicine, Jichi Medical School and University of Minnesota were the core research institutes. There was no core author or core journal or core institute in China up till now. However, core authors, core journals and core research institutes had come into being in foreign countries; they were mainly from the Euro-American developed countries and had done well in chronotherapy.

Bibliometrics↗

PubMed2005

[Application of sigmoid coloplasty in super-lower anastomosis].

OBJECTIVE: To assess the clinical value of sigmoid coloplasty of super-lower anastomosis. METHODS: Thirty-five patients underwent sigmoid coloplasty (treatment group), while 33 patients received straight sigmoidorectostomy (control group). Complication rate and anal function were observed and compared between the two groups. RESULTS: The complication rate was 17.1% and 21.2% in the study group and control group respectively (P> 0.05). Average stool frequency were 2 times (1-5.5 times) a day in the study group and 3.5 times (1-9 times) a day in the control group 12 months after operation (P< 0.01). The fecal continence and self-satisfaction were improved significantly in the study group than that of the control group(P< 0.01, respectively). The postoperative anal function score was 2.57 in the study group and 7.21 in the control group, there was significant difference between the two groups (P< 0.01). CONCLUSIONS: Compared with straight sigmoidorectostomy, sigmoid coloplasty applied in super-lower anastomosis can significantly improve the recovery of anal function without increasing complication rates.

Adult↗

PubMed2005

[Therapeutic options and prognosis of synchronous multiple primary colorectal carcinomas].

OBJECTIVE: To investigate the therapeutic principles and prognosis of synchronous primary colorectal carcinomas (SCC). METHODS: The data of 66 SCC patients surgically treated from 1984 to 2003 were retrospectively reviewed. RESULTS: The synchronous primary colorectal carcinomas were diagnosed and resected simultaneously in 65 patients except one that was misdiagnosed. Thirty patients underwent combined resection, 35 patients segmental resection. Sixty-two patients received radical resection, while three patients had palliative resection due to hepatic metastasis. The overall postoperative 3-, 5-, 10-year survival rates were 70.3%, 60.0%, 40.6%, respectively. In the patients who had simultaneous radical resection, the 3-, 5-, 10-year survival rates were 76.0%, 65.9%, 46.4% respectively. CONCLUSION: The extent of resection should be individually determined by the lesion location, extent and distance between the lesions, as well as the patient's general condition. More extensive bowel resection, such as total or subtotal colectomy are suggested for those patients with hereditary nonpolyposis colorectal carcinoma syndrome in order to reduce or avoid the risk of metachronous colorectal carcinoma. The postoperative survival in patients with synchronous primary colorectal carcinoma is similar to those with solitary lesion.

Adult↗

PubMed2005

Immunotoxins and cancer therapy.

In the past decade, an increased amount of clinically-oriented research involving immunotoxins has been published. Immunotoxins are a group of artificially-made cytotoxic molecules targeting cancer cells. These molecules composed of a targeting moiety, such as a ligand or an antibody, linked to toxin moiety, which is a toxin with either truncated or deleted cell-binding domain that prevents it from binding to normal cells. Immunotoxins can be divided into two categories: chemically conjugated immunotoxins and recombinant ones. The immunotoxins of the first category have shown limited efficacy in clinical trials in patients with hematologic malignancies and solid tumors. Within the last few years, single-chain immunotoxins provide enhanced therapeutic efficacy over conjugated forms and result in improved antitumor activity. In this review, we briefly illustrate the design of the immunotoxins and their applications in clinical trials.

Animals↗

PubMed2005

[The diagnostic value of serum carcinoma markers, fecal K-ras and p53 gene mutation in pancreatic cancers].

OBJECTIVE: To evaluate the diagnostic value of serum carcinoma markers CA19-9, CA242, CA50 and carcinoembryonic antigens (CEA), fecal K-ras and p53 gene mutation in pancreatic cancer. METHODS: We collected 136 new cases of pancreatic cancer and 240 patients with benign digestive diseases including 49 patients with benign pancreatic diseases diagnosed in Peking Union Medical College Hospital, Chinese Academy of Medical Sciences Tumor Hospital and Shenyang PLA General Hospital from February 2002 to March 2004. Blood samples were collected and serum carcinoma markers CA19-9, CA242, CA50 and CEA were measured. Fecal K-ras and p53 gene mutation were also measured. We decided the optimal cut-off points with receiver operating characteristic curves and calculated the areas under the curve (AUC). RESULTS: The AUC of serum CA19-9 and CA242 were 0.855 +/- 0.031 (95% CI 0.794 - 0.916) and 0.859 +/- 0.031 (95% CI 0.799 - 0.920) respectively. The optimal cut-off point for serum CA19-9 was 68 U/ml, with the sensitivity of 84.4% (98/116) and the specificity of 84.3% (145/172) for the diagnosis of pancreatic cancer. The optimal cut-off point for serum CA242 was 25 U/ml, with the sensitivity of 88.4% (84/95) and the specificity of 79.1% (144/182). The sensitivity of fecal K-ras mutation was 77.8%, and the specificity was 82.2%. The sensitivity and specificity of fecal p53 gene mutation were 27.8% and 95.2% respectively. The diagnostic scale of pancreatic cancer was calculated by four variables: serum CA19-9, CA242, fecal K-ras and p53, of which each variable deserved one point if measured positive. The optimal cut-off point for the scale was 2, and the AUC of the diagnostic scale was 0.946 +/- 0.017 (95% CI 0.912 - 0.980). CONCLUSIONS: Serum CA19-9 and CA242 are valuable diagnostic tools for pancreatic cancer. The diagnostic value will be further improved when they are combined with the measurement of fecal K-ras and p53 gene mutation.

Adolescent↗

PubMed2005

[Effects of nitrate application on alleviating photosynthesis restriction of Cinnamomum burmannii leaves under elevated CO2 concentration and enhanced temperature].

In this study, potted C. burmannii saplings were cultured in a top-closed chamber with elevated CO2 (+ CO2, 731 micromol x mol(-1)) and ambient CO2(CO2, 365 micromol x mol(-1)), and at diurnal temperature (day/night) 25/23 degrees C and 32/25 degrees C, respectively. The gas exchange, calculated photosynthesis parameter, Rubisco content, and activated state of Rubisco were examined. The results showed that under + CO2 and at 25/23 degrees C, the mean photosynthetic rate (Pnsat) of sapling leaves was 5.1% higher than that under + CO2 and at 32/25 degrees C. Temperature enhancement declined Pnsat, while nitrate addition increased it. Under + CO2, saplings had lower V(cmax) and J(max) at 32/25 degrees C than at 25/23 degrees C. Temperature enhancement under + CO2 also declined V(cmax) and J(max). Under + CO2, lower photorespiration rate (Rp) occurred in leaves, but temperature enhancement could increase Rp. Under + CO2, Rubisco content (NR) and its active site per unit leaf area (M) decreased as diurnal temperature changed from 25/23 degrees C to 32/25 degrees C. Meanwhile, nitrate addition could increase NR and M. It may be suggested that nitrate addition could alleviate the restriction of photosynthesis under elevated CO2 concentration and enhanced temperature.

Carbon Dioxide↗

PubMed2005

[Clinical use of quantitative DNA pathologic examination in eye neoplasms].

Quantitative DNA pathologic examination is an important content of quantitative pathology, which is to use cytochemistry quantitative analytical technique for quantitative analysis of patho-histological structure and intra-cellular DNA level. Quantitative determination of DNA in tumor cells as an objective quantitative index reflecting biological behavior of tumor cells and has an important significance for distinguishing precancerous lesions, borderline tumors, benign and malignant tumors; and for estimating the malignant degree and prognosis. This review introduces the study about DNA quantitative analysis used in clinical pathology of eye neoplasms.

DNA, Neoplasm↗

PubMed2005

[Secondary succession characteristics of vegetations on reclaimed land inside Chongming wetland seawall].

National reserve Chongming Dongtan wetland was designated as an important international wetland (ramsar site) in 2002. The area outside 98 seawalls is the core area of the reserve, while their inside is the experimental area. A wetland restoration project was started in June 2003, and a large pond behind the seawall was unwatered, which changed the soil condition and appeared drought and salinization. The vegetations presented typical secondary succession, and Aeluropus littoralis and Suaeda glauca invaded the area originally dominated by reed. From July 2003 to April 2004, the soil moisture content and salinity of 15 samples were determined, with the biomass, height, density, and coverage of each kind of vegetations measured. The results showed that the vegetation layout had become an obviously zonary distribution of Aeluropus littoralis-Aeluropus littoralis/Suaeda glauca-Suaeda glauca/Phragmites communis-Phragmites communis community. Suaeda glauca gradually extended to the reed area, and became the dominant species of the area, with an average biomass of 2003 415.4 g x m(-2) in autumn, and of 2004 391.53 g x m(-2) in spring. The biomass and height of Suaeda glauca increased, and its density was getting stable, suggesting that the plant had strong growth ability in drought area.

Biodiversity↗

PubMed2004

A draft sequence for the genome of the domesticated silkworm (Bombyx mori).

We report a draft sequence for the genome of the domesticated silkworm (Bombyx mori), covering 90.9% of all known silkworm genes. Our estimated gene count is 18,510, which exceeds the 13,379 genes reported for Drosophila melanogaster. Comparative analyses to fruitfly, mosquito, spider, and butterfly reveal both similarities and differences in gene content.

Algorithms↗

PubMed2004

Silencing of SARS-CoV spike gene by small interfering RNA in HEK 293T cells.

Two candidate small interfering RNAs (siRNAs) corresponding to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spike gene were designed and in vitro transcribed to explore the possibility of silencing SARS-CoV S gene. The plasmid pEGFP-optS, which contains the codon-optimized SARS-CoV S gene and expresses spike-EGFP fusion protein (S-EGFP) as silencing target and expressing reporter, was transfected with siRNAs into HEK 293T cells. At various time points of posttransfection, the levels of S-EGFP expression and amounts of spike mRNA transcript were detected by fluorescence microscopy, flow cytometry, Western blot, and real-time quantitative PCR, respectively. The results showed that the cells transfected with pEGFP-optS expressed S-EGFP fusion protein at a higher level compared with those transfected with pEGFP-S, which contains wildtype SARS-CoV spike gene sequence. The green fluorescence, mean fluorescence intensity, and SARS-CoV S RNA transcripts were found significantly reduced, and the expression of SARS-CoV S glycoprotein was strongly inhibited in those cells co-transfected with either EGFP- or S-specific siRNAs. Our findings demonstrated that the S-specific siRNAs used in this study were able to specifically and effectively inhibit SARS-CoV S glycoprotein expression in cultured cells through blocking the accumulation of S mRNA, which may provide an approach for studies on the functions of SARS-CoV S gene and development of novel prophylactic or therapeutic agents for SARS-CoV.

Cell Line↗