[Professor Tong Xiao-Lin's experience in syndrome differentiation and treatment for high fever].
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Diagnosis, Differential↗
Biomedical subjects
Yan Du
Publications and source records attributed to Yan Du.
Toxin-coregulated pilus-loaded microparticles as a vaccine against Vibrio cholerae O139.
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Animals↗
Fabrication of integrated microelectrodes for electrochemical detection on electrophoresis microchip by electroless deposition and micromolding in capillary technique.
A new method for the fabrication of an integrated microelectrode for electrochemical detection (ECD) on an electrophoresis microchip is described. The pattern of the microelectrode was directly made on the surface of a microscope slide through an electroless deposition procedure. The surface of the slide was first selectively coated with a thin layer of sodium silicate through a micromolding in capillary technique provided by a poly(dimethylsiloxane) (PDMS) microchannel; this left a rough patterned area for the anchoring of catalytic particles. A metal layer was deposited on the pattern guided by these catalytic particles and was used as the working electrode. Factors influencing the fabrication procedure were discussed. The whole chip was built by reversibly sealing the slide to another PDMS layer with electrophoresis microchannels at room temperature. This approach eliminates the need of clean room facilities and expensive apparatus such as for vacuum deposition or sputtering and makes it possible to produce patterned electrodes suitable for ECD on microchip under ordinary chemistry laboratory conditions. Also once the micropattern is ready, it allows the researchers to rebuild the electrode in a short period of time when an electrode failure occurs. Copper and gold microelectrodes were fabricated by this technique. Glucose, dopamine, and catechol as model analytes were tested.
Journal Article↗
Bioavailability of granulocyte colony-stimulating factor administered enterally to suckling mice.
The developing fetal and neonatal gastrointestinal (GI) tract is influenced by many growth factors, including epidermal growth factor (EGF), insulin-like growth factor (IGF), transforming growth factor (TGF), and erythropoietin (Epo). Granulocyte colony-stimulating factor (G-CSF), typically regarded as a hematopoietic growth factor, might also be included because it exists in high concentrations in amniotic fluid, colostrum, and human milk, and because granulocyte CSF receptors (G-CSF-R) are abundantly expressed on the villous enterocytes of the developing intestine. As a first step toward understanding whether the effects of G-CSF on the GI tract were local or systemic, we sought to determine whether recombinant human G-CSF (rhG-CSF) administered enterally to suckling mice, is absorbed into the circulation, and if so, whether the G-CSF-R is essential for this absorption. We enterally administered rhG-CSF to suckling mice, selecting a daily dose based on the amount of G-CSF normally swallowed by the fetus and neonate (3 ng), or in other mice, a dose of G-CSF 100 times larger (300 ng). Pups were tested at either 5-7 days of age, or at 14-16 days of age. C57BL/6 x 129SvJ mice were used. Some mice had a targeted null mutation in the G-CSF-R gene, producing a non-functional G-CSF-R protein. At intervals following the enteral G-CSF dosing, G-CSF concentrations in plasma were measured by specific ELISA. The bioavailability of G-CSF was invariably <1%, regardless of the dose of rhG-CSF given, the age of the pups, or whether they had a functional G-CSF-R. After enteral administration of rhG-CSF to suckling mice, only minimal quantities of G-CSF are absorbed into the circulation, and the G-CSF-R is not essential for this absorption.
Age Factors↗
Messenger RNA expression of granulocyte colony-stimulating factor receptor isoforms in the fetus.
Granulocyte colony-stimulating factor (G-CSF) is a growth factor known to support the proliferation, differentiation, and survival of cells of the neutrophil lineage. G-CSF affects these cells after binding to its specific receptor, G-CSF-R, which exists in seven isoforms. While information exists about the distribution of these isoforms in hematopoietic cells and placenta, G-CSF-R isoforms on non-hematopoietic fetal tissues have not been described. Using RT-PCR, we analyzed a variety of human fetal tissues ranging from 6 to 18 weeks gestation. Isoforms I and III were present in all tissues, and the expression of isoform III varied with gestational age. The remaining isoforms were variably expressed in relation to tissue type and gestational age. Thus in the human fetus, G-CSF-R isoform I is the predominant form expressed on non-hematopoietic and hematopoietic tissues.
Fetus↗
[Distribution of hepatitis B virus genotypes and its clinical significance in Guangxi].
OBJECTIVE: To understand the distribution of hepatitis B virus genotype in Guangxi and its clinical significance. METHODS: Nested polymerase chain reaction (nPCR) was used for amplification of HBV DNA in sera of asymptomatic carrier (ASC) of hepatitis B virus (HBV) and patients with different liver diseases from southern and northern Guangxi. Specimens from 161 subjects were positive for HBV DNA and HBV genotype was determined by using restriction fragment length polymorphism analysis, direct sequencing or cloning sequencing. RESULTS: The prevalence of genotype A was 3.7% in all samples and that of genotype B, C and D was 21.7%, 72.7% and 1.2%, respectively. No other genotypes (such as genotype E, F, G, H) were found. The prevalence of genotype C showed an increasing trend in ASC, chronic hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC) group; in contrast, the prevalence of genotype B showed an opposite trend, although no statistically significant difference was observed, except between ASC and HCC (P=0.05). The HBeAg positive rate was higher, and the anti-HBe positive rate was lower in patients with chronic genotype C infection than in those with genotype B (P<0.05 for both). Liver function test (ALT) abnormality was more severe in genotype C group than in genotypes A and B groups having acute or chronic infection (P<0.01 for all comparisons). The prevalence of genotype C in southern Guangxi was higher than that in northern Guangxi. In contrast, the prevalence of genotype B in southern Guangxi was lower than that in northern Guangxi. CONCLUSIONS: 1. The predominant HBV genotypes in Guangxi were genotypes B and C. The major genotype in southern Guangxi was genotype C; while that in northern Guangxi was genotype B, which implied that the distribution of HBV genotype C was consistent with the incidence of HCC in Guangxi. 2. Genotype C maybe associated with development of severe liver diseases including HCC. 3. Genotype A,D and B+C were mostly found in acute, hepatitis and chronic hepatitis group.
Carcinoma, Hepatocellular↗
Comparison of Chinese field strains of avian leukosis subgroup J viruses with prototype strain HPRS-103 and United States strains.
Eight Chinese field strains of subgroup J avian leukosis viruses (ALV-J) were isolated from broilers or parent stocks during January 1999 to April 2001. One strain, SD9902, was an acute transforming virus, able to induce typical myelocytomatosis in 22-38 days after inoculation of 1-day-old meat-type chicks. The envelope protein and 3'-untranslated region (UTR) of the eight field strains were compared with the U.K. prototype HPRS-103 and several U.S. field strains isolated in 1993-97. All Chinese strains shared an almost identical deletion with the U.S. strain 4817 in the E element region of 3'-UTR when compared with the prototype HPRS-103, indicating that they have a very close phylogenic relationship. Every year, China has to import grandparent stocks of meat-type chickens, mainly from the United States. Chinese isolates should represent a part in the phylogenic tree of U.S. ALV-J evolution. Envelope protein gp85 amino acid sequence analysis demonstrated that, interestingly, all recent Chinese isolates were more closely related to HPRS-103 and the earliest U.S. isolates but not to the late U.S. isolates. The result implies that envelope gp85 may not have diverged from prototype and older strains. It is also possible that some recently imported birds could have been infected by the older viruses that were introduced in the late 1990s.
Abattoirs↗