Biomedical subjects

Xinhong Li

Publications and source records attributed to Xinhong Li.

6 recordsLinked to original sources

PubMed2006

Full-field quantitative phase imaging by white-light interferometry with active phase stabilization and its application to biological samples.

We report a Koehler-illumination-based full-field, actively stabilized, low-coherence phase-shifting interferometer, which is built on a white-light Michelson interferometer. By using a phase-stepping technique we can obtain full-field phase images of the sample. An actively stabilized phase-lock circuit is employed in the system to reduce phase noise. An application to human epithelial cells (HeLa cells) is achieved in our experiment. The advancement of this technique rests in its ability to take images of unstained biological samples quantitatively and on a nanometer scale.

Equipment Design↗

PubMed2006

Characterization of truncated hantavirus nucleocapsid proteins and their application for serotyping.

Hemorrhagic fever with renal syndrome (HFRS) is a fulminant infectious disease characterized by fever, hemorrhage, renal impairment, and thrombocytopenia. Hantaviruses associated with this belong to different serotypes: Hantaan (HTN), Seoul (SEO), Dobrava/Belgrade (DOB), and Puumala (PUU). The first two, HTN and SEO, are endemic in China. To investigate the epidemiology of HFRS and virus transmission in China, we constructed prokaryotic plasmids encoding truncated recombinant HTN and SEO nucleocapsid proteins (NPs), which lacked 154 amino acid (aa), 99 aa, or 49 aa in the N-terminal region, respectively. After expression, the truncated rNPs were tested as serotyping antigens, particularly for use in the enzyme-linked immunosorbent assay (ELISA). In addition, 68 acute and 52 convalescent sera were collected from HFRS patients from Harbin, Lantian, and Kaifeng regions in China in 2004, which had hantavirus specific antibodies by IFA. A neutralization test was used to differentiate these, which showed that 73 were due to HTN infection, 33 to SEO infection, and 14 undetermined. By ELISA, the truncated rNPs, that lacked 99 (rNP100) or 49 (rNP50) N-terminal amino acids of the NPs of HTN and SEO, were able to differentiate HTNV and SEOV-specific immune sera, but the rNP155 could not. Particularly, the ELISAs based on the rNP50s had a result comparable to PRNT. Thus, the rNP50 is recommended as efficient serotyping antigen for hantavirus infection diagnosis by ELISA.

Animals↗

PubMed2006

Association between HIV Type 1-specific T cell responses and CD4+ T cell counts or CD4+:CD8+ T cell ratios in HIV Type 1 subtype B infection in China.

CD4+ T cell counts and CD4+:CD8+ T cell ratios represent key determinants of HIV disease progression and infectivity. However, the relationship between the HIV-1-specific cytotoxic T lymphocyte (CTL) response and these determinants has not been elucidated for all HIV-1B and HIV-1C proteins. In the present study, virusspecific T cell responses to HIV-1B and HIV-1C proteins were analyzed with interferon gamma (IFN-gamma) enzyme- linked immunospot (ELISpot) assays using synthetic overlapping peptides corresponding to naturally occurring HIV-1B and HIV-1C consensus sequences. For Gag/Gag p24/Gag p17, a correlation between T cell responses and CD4+ T cell count in HIV-1 clade B and clade C was seen: elevated T cell response resulted in higher CD4+ T cell production. A statistically significant correlation between the Pol-specific T cell response and CD4+ T cell counts was also found in HIV-1 subtype C. For all HIV-1B and HIV-1C proteins, a correlation between the HIV-1-specific T cell response and CD4+:CD8+ T cell ratios was found for Tat and Pol proteins. CD4+ T cell counts in patients with Tat and/or Rev T cell response were higher than in patients without Tat and/or Rev T cell response. We suggest that this correlation within HIV-1B and HIV-1C Gag p24/Gag p17 responses makes the Gag p24/Gag p17 region a potential vaccine candidate and that HIV-1-specific CTL epitopes toward Pol are important in controlling HIV-1 infection; we emphasize that future vaccination strategies should include these early antigens, Tat and Rev.

Adolescent↗

PubMed2006

Conductive super-hydrophobic surfaces of polyaniline modified porous anodic alumina membranes.

A conductive polymer polyaniline (PANI) was employed to achieve surfaces of both super-hydrophobic and conductive on NaOH etched porous anodic alumina (PAA) membranes. The surfaces exhibit micro- and nanostructures. In the PANI modified PAA membrane, PANI is mainly emeraldine. After the membrane was immersed in HCl, the content of the protonated nitrogen increased, which increased the conductivity.

Aluminum Oxide↗

PubMed2002

[Complete genome sequence of 84FLi, a Hantaan virus strain isolated from the liver of fetus aborted by a pregnant women with hemmorrhagic fever with renal syndrome].

OBJECTIVE: To study the complete genome sequence of the Chinese Hantaan virus vaccine strain 84FLi and learn about its molecular characters. METHODS: The virus strain 84FLi was isolated from the liver of a fetus aborted by pregnant women with hemorrhagic fever with renal syndrome. The cDNAs of L M and S segments were amplified fragment by fragment using RT-PCR. The purified PCR products were sequenced directly or cloned into pMD18-T vector and then sequenced. RESULTS: The complete genome of strain 84FLi was composed of L ( 6 533 bp) M (3 616 bp) and S (1 688 bp) coding 2151 1135 and 429 amino acids respectively. The entire sequence composition was 3830A 2050C 2510G and 3447T the GC and AT contents were 38.52% and 61.48%. Homology analysis showed that the homologies of 84 FLi S segment nucleotide sequences with strain RG9 (isolated in Guangzhou) and strain Chen4 (isolated in Anhui) were 99.6%. There were 83.7% 84.0% and 87.2% nucleotide sequences homology with the three segments of Hantaan virus foreign standard strain 76-118 while the amino acids sequences homology with those of 76-118 were 97.5% 96.0% and 97.9% respectively. CONCLUSION: The strain 84FLi is highly related to other Chinese Hantaan virus isolates and is in the same subtype with the other two Chinese isolates RG9 and Chen4.

Amino Acid Sequence↗

PubMed2002

[Effects of probiotics additives EM on growth metabolism and immune function of blue fox in growth phase].

Different doses of probiotics EM were added to the diets of blue fox in its growth phase to study the effects of EM additives on its growth, digestion metabolism and immune function. The results showed that with EM additives applied, the ingestion and average daily gains were increased remarkably (P < 0.05). The apparent digest rate of crude fibre, crude protein, mineral elements Ca, P and NPU could be increased (P < 0.05) and correlated with its dose, and the digest rates of the later four targets in group III were increased by 8.21%, 16.27%, 9.82%, and 12.13%, respectively. EM additives could not increase the digest rate of ether extral and N-free extract. Disease of diarrhoea and blood in stool could be prevented and cured, and immune function and the survival rate of fox in growth phase could be increased remarkably. EM, which a kind of efficient, safe and environmental protection additives, can be extended and applied in farming of fur animals.

Animals↗