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Biomedical subjects

G Zeng

Publications and source records attributed to G Zeng.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Studies on decomposed crop residues by FTIR differential analysis].

The decomposing process of corn leaf residues (CLR) was studied by FTIR differential analysis, and the differential spectra were compared with normal spectra. The result showed that the purification process to remove inorganic matters from decomposed CLR could be omitted when differential analysis is used, and the differential spectra were clear and distinct. As far as the studies of decomposed crop residues, the FTIR differential analysis was a convenient and forthright method.

Spectroscopy, Fourier Transform Infrared↗
PubMed1998

A breast and melanoma-shared tumor antigen: T cell responses to antigenic peptides translated from different open reading frames.

Infusion of TIL586 along with IL-2 into the autologous patient with metastatic melanoma resulted in the objective regression of tumor. Here, we report that screening a cDNA library from the 586mel cell line using CTL clones derived from TIL586 resulted in the isolation of a gene, CAG-3 (cancer Ag gene 3). Sequence analysis revealed that CAG-3 encodes an open reading frame identical to NY-ESO-1, which was recently reported to be recognized by autologous serum from a patient with esophageal cancer. Thus, NY-ESO-1 appears to be an immune target for both Ab- and T cell-mediated responses. Significantly, NY-ESO-1-specific CTL clones were capable of recognizing two HLA-A31-positive fresh and cultured breast tumors. To our knowledge, this represents the first direct demonstration that tumor-specific CTL clones can recognize both breast and melanoma tumor cells. A 10-mer antigenic peptide ESO10-53 (ASGPGGGAPR) was identified from the normal open reading frame of NY-ESO-1 based on its ability to sensitize HLA-A31-positive target cells for cytokine release and specific lysis. Interestingly, two additional CTL clones that were sensitized with NY-ESO-1 recognized two overlapping antigenic peptides derived from an alternative open reading frame of the same gene. These findings indicate that CTLs simultaneously responded to two different gene products translated from the normal and alternative reading frames of the same gene. Understanding of this mechanism by which the alternative reading frame is translated may have important implications in tumor immunology.

Amino Acid Sequence↗
PubMed1998

Development of a retrovirus-based complementary DNA expression system for the cloning of tumor antigens.

A new retroviral system has been developed for the generation of a cDNA library and the functional cloning of tumor antigens. These retroviral vectors contain a cytomegalovirus promoter in the 5' long terminal repeat, an extended packaging signal for rapid production of high-titer retroviral particles, and many convenient cloning sites for cDNA library construction. The vesicular stomatitis virus G protein has been used to generate pseudotype retroviral particles to enable efficient viral infection. Using this system, viral titers in the range of 10(6) colony-forming units/ml could be generated routinely, and a high transduction efficiency in human primary cells, including fibroblasts, was achieved. In addition, a new procedure has been devised for screening a retrovirus-based cDNA library without a functional selection. The utility of this system was demonstrated by constructing a retrovirus-based cDNA library and re-isolating the NY-ESO-1 tumor antigen from a cDNA library using an antigen-specific CTL. This approach can facilitate the identification of novel tumor antigens recognized by T cells without knowledge of MHC class I restriction elements and is generally applicable for the isolation of any gene as long as a biological assay is available.

3T3 Cells↗
PubMed1998

Isolation and functional analysis of the promoter of the rat CMP-NeuAc:GM3 alpha2,8 sialyltransferase gene 1.

A 2.1-kb 5'-flanking fragment of the rat CMP-NeuAc:GM3 alpha2,8 sialyltransferase (GD3-synthase) gene was cloned by the genomic walking procedure. The promoter activity of the fragment was assessed in F-11 cells by transient transfection and the locations for the basal and maximal promoter activities were defined. Primer extension analysis identified a transcription start site approximately 98 bp upstream of the ATG start codon. DNA sequence analysis of the promoter revealed a number of consensus binding sites for known transcription factors such as SP1, AP1, NFkappaB, C/EBP and TFIID, and a repeat GC-GT sequence motif seen for the formation of Z-type DNA. Both TATA and CCAAT boxes were not found in the promoter. Our results from deletion constructs suggested that both positive and negative cis-acting regulatory regions were present in this TATA-less promoter of the rat GD3-synthase gene.

Animals↗
PubMed1998

Transgenic animals with inducible, targeted gene expression in brain.

Several inducible gene expression systems have been developed in vitro in recent years to overcome limitations with traditional transgenic mice. One of these, the tetracycline-regulated system, has been used successfully in vivo. Nevertheless, concerns remain about the ability of this system to direct high levels of transgene expression in vivo and to enable such expression to be turned on and off effectively. We report here the generation, using a modified tetracycline-regulated system under the control of the neuron-specific enolase promoter, of several lines of mice that direct transgene expression to specific brain regions, including the striatum, cerebellum, CA1 region of the hippocampus, or deep layers of cerebral neocortex. Transgene expression in these mice can be turned off completely with low doses of doxycycline (a tetracycline derivative) and driven to very high levels in the absence of doxycycline. We demonstrate this tissue-specific, inducible expression for three transgenes: those that encode luciferase (a reporter protein) or DeltaFosB or the cAMP-response element binding protein (CREB) (two transcription factors). The various lines of transgenic mice demonstrate an inducible system that generates high levels of transgene expression in specific brain regions and represent novel and powerful tools with which to study the functioning of these (or potentially any other) genes in the brain.

Animals↗
PubMed1998

[Study on the relative absorption of food carbohydrate in healthy adults].

The absorption of food carbohydrate was determined with breath hydrogen test (BHT) in healthy adults. When the absorption of lactulose was assumed as 0, the absorption of food carbohydrates were as follows: 100% for rice with ground lean pork; 98% for rice; 85% for bread; 58% for corn and 30% for red potato. The absorption of food carbohydrate was positively related to the oral-colon transit time (OCTT, r = 0.8790) and the peak hydrogen time (PHT, r = 0.6745), and was negatively related to the peak hydrogen value (PHV, r = -0.6468) and to the hydrogen producing percentage (H2 > 1.8 mg/m3, r = -0.8679). The breath hydrogen test can be used in estimating the absorption of food carbohydrate in human body because this method is safe, non-invasive, reproducible and accurate.

Adult↗
PubMed1998

Infectious disease surveillance in China.

A national system of infectious disease surveillance was established in 1959 in China. Now it consists of three subunits, namely, national disease reporting system (NDRS), nationwide disease surveillance points (DSPs), and surveillance network for specific infectious diseases. There are 35 notifiable infectious diseases, which are divided into Classes A, B, and C. The functions of the surveillance include explaining the natural history of infectious diseases, describing the distribution of case occurrence, triggering disease-control effort, monitoring epidemic of infectious diseases during natural disasters, predicting and controlling epidemics and providing the base of policy adjustment.

China↗
PubMed1997

Cloning of the cDNA coding for rat brain CMP-NeuAc:GD3 alpha2-8 sialyltransferase.

The cDNA coding for GT3-synthase has been cloned from a rat fetal brain cDNA library. The complete nucleotide sequence and the deduced amino acid sequence of the rat GT3-synthase cDNA were highly homologous to those of the mouse GT3-synthase. Quantitative RT-PCR showed that, as a key enzyme for the synthesis of 'c'-series gangliosides, the expression of GT3-synthase was developmentally regulated in embryonic rat brains.

Amino Acid Sequence↗
PubMed1997

[A study of therapeutic efficacy of Koukangning gargle in the treatment of oral mucositis].

A study of therapeutic efficacy was carried out in 118 patients with oral mucositis (recurrent oral aphthous ulceration, erosive lichen planus, herptic stomatitis and infectious oral mucosal hematoma) at random. As a topical medication, Koukangning gargle was applied to 59 patients of the experimental group, 29 patients of the control group 1 applied Dobell's solution to rinse their mouths, and 30 patients of the control group 2 applied Koutai solution. A satisfactory result was observed in the experimental group, its effectiveness and effective rates rose more than those of control group 1 at both treatments for 3 days and 6 days. Between the two groups, there were markedly significant difference (P < 0.005, P < 0.01, P < 0.005, P < 0.005). Koukangning gargle was nontoxic and no side-effects in the clinical tests. Its efficacy was no significant difference compared with the control group 2. Experimental study demonstrates that it possesses anti-inflamation effect and excellent antibiotic effect, therefore it is a new gargle for rinse mouth combined traditional Chinese medicine with Western medicine.

Anti-Infective Agents, Local↗
PubMed1997

[Preparation and property investigations of nanosized titanium oxide microcrystals].

A naosized TiO2 powder was successfully prepared by the hydrolysis of titanium isopropoxide through sol-gel process. The microstructure of TiO2 powder was investigated by transmission electron microscopy and X-ray diffraction. Both anatase and rutile phases were found in TiO2 powder annealed for 1 hour at 600 degrees C. The characteristics of X-ray photoelectron spectra and infrared spectra could be affected by the size and aggregation state of the microsrystalc constituting the TiO2 powder.

English Abstract↗
PubMed1997

Induction of proto-oncogenes during 3-deazaadenosine-stimulated differentiation of 3T3-L1 fibroblasts to adipocytes: mimicry of insulin action.

3-Deazaadenosine (DZA) mimicked the molecular action of insulin in the induction of 3T3-L1 fibroblasts to differentiate into adipocytes. The molecular effects of DZA were compared with insulin, which served as a positive control, on the expression of proto-oncogenes during the initial stage of differentiation of 3T3-L1 fibroblasts. Treatment of confluent 3T3-L1 fibroblasts with DZA or insulin produced a rapid but-transient expression of mRNA for proto-oncogenes c-fos and c-jun within 30-60 min. The mRNA of c-myc increased for 2 h and then decreased 4 h after treatment. Electrophoretic mobility shift assays showed a heightened increase in the appearance of transcription factors AP-1 and AP-2. The increase was detectable as early as 1 h after the treatment with either DZA or insulin and was maintained for 6 h. 3T3-L1 cells stably transfected with the promotor of c-fos linked to a CAT reporter gene showed an increase in CAT activity in response to DZA in a time- and dose-dependent manner. In cells stably transfected with antisense c-fos, neither DZA nor insulin was able to induce a differentiation response. The early transcription of c-fos, c-jun, and c-myc proto-oncogenes and the increased expression of transcription factors AP-1 and AP-2, induced by DZA and insulin, appear to be crucial events in the differentiation of the 3T3-L1 fibroblasts to adipocytes.

3T3 Cells↗