Biomedical subjects

Hong Cao

Publications and source records attributed to Hong Cao.

59 records · Page 4Linked to original sources

PubMed2002

[Treatment of lumbar spondylolisthesis by Socon internal fixator: report of 18 cases].

OBJECTIVE: To evaluate the therapeutic effect of Socon transpedicle internal fixators in the treatment of spondylolisthesis in the lumbar spine. METHODS: Fixation with Socon internal fixators along with posterior decompression and fusion was performed in 18 patients with degenerative spondylolisthesis in the lumbar spine. The symptoms, signs and X-ray manifestations observed preoperatively and postoperatively were compared, and a follow-up study of all cases lasting for 6 to 18 month was conducted. RESULTS: Anatomical restoration of the involved vertebrae was achieved in all the cases, of them 15 had out-standing and 2 had fairly good clinical results without incidences of any complications during or after the operation. CONCLUSION: Socon internal fixator is an excellent modality for treatment of lumbar spondylolithesis.

Adult↗

PubMed2001

Molecular Constants for the v=0, b(1)Sigma(g)(+) Excited State of O(2): Improved Values Derived from Measurements of the Oxygen A-Band Using Intracavity Laser Spectroscopy.

High-resolution intracavity laser spectroscopy (ILS) absorption measurements have been made on the b-X oxygen electronic transition (the A-band) which has bandheads occurring in the region of 13 165 cm(-1). The positions of the lines were determined to an accuracy that is based on calibration with I(2) absorption lines using the Laboratoire Aimé Cotton (Orsay) Atlas as reference. Based on the ILS measurements and the more accurately determined positions given by L. R. Brown and C. Plymate (J. Mol. Spectrosc. 199, 166-179 (2000)) and with the (3)Sigma(g)(-) ground state molecular constants fixed at the values determined by G. Rouillé et al. (J. Mol. Spectrosc. 154, 372-382 (1992)), the following values (in cm(-1)) were found for the molecular constants: T(0)=13122.2524(1); B(0)=1.391244(2); D(0)=5.352(4)x10(-6); and H(0)=-1.2(2)x10(-11). These results are compared with values derived from fits of the line positions listed in several other studies of this transition. Copyright 2001 Academic Press.

Journal Article↗

PubMedDate not supplied

A new class of RNA-binding oligomers: peptoid amide and ester analogues.

Replication of human immunodeficiency virus type 1 (HIV-1) requires specific interactions of Tat protein with the trans-activation responsive region (TAR) RNA, a 59-base stem-loop structure located at the 5'-end of all HIV mRNAs. Here we report the design, synthesis and in vitro activities of oligopeptoid amide and ester analogues which bind TAR RNA with high affinities. These results show that we have identified a new class of unnatural oligomers for RNA targeting.

Amides↗

PubMedDate not supplied

Orientation and affinity of HIV-1 Tat fragments in Tat-TAR complex determined by fluorescence resonance energy transfer.

The human immunodeficiency virus (HIV-1) encodes a transcriptional activator protein, Tat, which is expressed early in the viral life cycle and is essential for viral gene expression, replication, and pathogenesis. Tat interacts with the transactivation responsive region (TAR) RNA, a 59-base stem-loop structure located at the 5'-end of all HIV mRNAs. Tat-derived peptides that contain the basic arginine-rich region of Tat are able to form in vitro complexes with TAR RNA, and these peptides provide a well-characterized system for understanding the mechanism of RNA-protein recognition. It is not known how RNA-binding Tat peptides are folded or docked in the Tat-TAR complex, and to what extent structural reorganization occurs upon TAR binding. To address these questions, we developed a fluorescence resonance energy transfer (FRET) system to analyze the interactions between TAR RNA and a Tat protein fragment (aa 38-72) uniquely labeled with donor and acceptor dye molecules, respectively. Using this FRET assay, we determined the binding affinity of Tat (47-58) and Tat (38-72) for TAR RNA under physiological conditions. We also delineated the distance between the N- and C-terminus of Tat (38-72) and the distance between the two termini and the 5' end of TAR when Tat (38-72) is bound to TAR. Our results suggest that the N- and C-termini of Tat (38-72) are close to each other when the peptide is folded and that the peptide does not go through a large structural change upon TAR binding.

Amino Acid Sequence↗

PubMedDate not supplied

Design, microwave-assisted synthesis, and photophysical properties of small molecule organic antennas for luminescence resonance energy transfer.

A highly efficient microwave-assisted method was successfully developed for the synthesis of a library of carbostyril analogues. The reaction time for synthesis of carbostyril analogues was drastically reduced from a reported 18-58 h to only 80 min. Compounds obtained directly from each synthesis were more than 90% pure and did not require any further purification. On the basis of the fluorescence spectra of the compounds in the initial library, four carbostyril analogues were designed. Two of these analogues showed very favorable fluorescence profiles and have the potential to be used as small molecule organic antennas for LRET studies.

Combinatorial Chemistry Techniques↗