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Biomedical subjects

Lin Hua

Publications and source records attributed to Lin Hua.

5 recordsLinked to original sources

Cyclooxygenase-2 inhibition increases mortality, enhances left ventricular remodeling, and impairs systolic function after myocardial infarction in the pig.

BACKGROUND: Cyclooxygenase (COX)-2 expression in the heart increases after myocardial infarction (MI). In murine models of MI, COX-2 inhibition preserves left ventricular dimensions and function. We studied the effect of selective COX-2 inhibition on left ventricular remodeling and function after MI in a pig model. METHODS AND RESULTS: Twenty-two pigs were assigned to COX-2 inhibition with a COX-2 inhibitor (COX-2i; celecoxib 400 mg twice daily; n=14) or a control group (n=8). MI was induced by left circumflex coronary artery ligation, and the animals were euthanized 6 weeks later. Cardiac dimensions and function were assessed with echocardiography and conductance catheters. Infarct size and collagen density were analyzed with triphenyltetrazolium chloride staining and picrosirius red staining, respectively. COX-2 inhibition increased mortality compared with controls (50% versus 0%, P=0.022), whereas infarct size was similar (13.1+/-0.7% versus 14.1+/-0.1%, P=0.536). The decrease in thickness of the infarcted myocardial wall was more pronounced in the COX-2i group (60.6+/-9.6% versus 36.2+/-5.7%, P=0.001). End-diastolic volume was higher in the COX-2i group (133.9+/-33.5 versus 91.1+/-24.0 mL; P=0.021), as was the end-systolic volume at 100 mm Hg (81.7+/-27.8 versus 56.3+/-21.1 mL; P=0.037), which indicates that systolic function was more severely impaired. Infarct collagen density was lower after COX-2i treatment (25.3+/-3.9 versus 56.1+/-23.8 gray value/mm2; P=0.005). CONCLUSIONS: In pigs, COX-2 inhibition after MI is associated with increased mortality, enhanced left ventricular remodeling, and impaired systolic function, probably due to decreased infarct collagen fiber density.

Animals↗

UV embossed polymeric chip for protein separation and identification based on capillary isoelectric focusing and MALDI-TOF-MS.

This paper demonstrates a ultraviolet (UV)-embossed polymeric chip for protein separation by capillary isoelectric focusing (CIEF) and identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The polymeric chip was replicated by a UV-embossing technique using a soft rubber mold. Five diverse widely investigated families of UV-cured formulations were examined for MALDI ionization efficiency of bovine serum albumin (BSA) samples spotted on the polymer surfaces. The signal and signal-to-noise ratio from the polyester formulation were each 12 times those obtained with PMMA (a commonly used polymer material for MALDI) at picomole sample concentration. A polyester chip was successfully used to carry out CIEF to separate proteins, followed by MALDI-TOF-MS identification. Issues related to the successful chip fabrication and protein separation and identification are discussed.

Electrophoresis, Capillary↗

Microwave-assisted specific chemical digestion for rapid protein identification.

We have developed a rapid microwave-assisted protein digestion technique based on classic acid hydrolysis reaction with 2% formic acid solution. In this mild chemical environment, proteins are hydrolyzed to peptides, which can be directly analyzed by MALDI-MS or ESI-MS without prior sample purification. Dilute formic acid cleaves proteins specifically at the C-terminal of aspartyl (Asp) residues within 10 min of exposure to microwave irradiation. By adjusting the irradiation time, we found that the extent of protein fragmentation can be controlled, as shown by the single fragmentation of myoglobin at the C-terminal of any of the Asp residues. The efficacy and simplicity of this technique for protein identification are demonstrated by the peptide mass maps of in-gel digested myoglobin and BSA, as well as proteins isolated from Escherichia coli K12 cells.

Animals↗

A standardized surgical technique for mastoscopic axillary lymph node dissection.

To standardize the surgical technique for mastoscopic axillary lymph node dissection (MALND). Mastoscopic lymph node dissection was performed consistently by a group of surgeons in 316 cases of breast cancer. The mean operation time was 46.7 minutes with minimal bleeding, and the median number of lymph nodes dissected at each operation was 17.0. There were no operative complications in any case, nor did trocar implantation or tumor diffusion occurring during the mean follow-up time of 15.1 months. MALND is distinctive and practicable in operative anatomy as well as safe and convenient. The location of critical anatomy such as the intercostobrachial nerve, lateral thoracic artery, medial thoracic nerve, and thoracoepigastric vein should be clearly identified to avoid damage to them, so that is the great advantage of MALND.

Adult↗