Biomedical subjects

Q Ye

Publications and source records attributed to Q Ye.

202 records · Page 12Linked to original sources

PubMedDate not supplied

Identification of a channel catfish, Ictalurus punctatus (Rafinesque), leukocyte-specific leucine zipper protein.

Five clones isolated from a channel catfish cDNA library were each reactive with monoclonal antibodies (mAbs) C3-1 and 51A only. The size of the cDNA inserts from C3-1 and 51A positive clones was 2.5 Kb and identical based on sequence analysis. Monoclonal antibodies C3-1 and 51A specifically reacted with the expressed product of the 2.5 Kb cDNA clone. The complete DNA sequence indicated that the 2.5 Kb cDNA encoded an approximately 50 Kd protein molecule consisting of 445 amino acids. Sequence analysis showed that this putative protein was a potential leucine-zipper DNA binding protein. Comparison of the deduced amino acid sequence demonstrated homology (14.6 to 19.5%) throughout the sequence of the catfish protein with a group of cytoplasmic-leucine zipper containing proteins of humans; paraneoplastic cellebellar degeneration related (cdr) antigen 2 and 3 with 39.8 to 56.3% homology in the leucine-zipper motif (amino acids 52 through 175 in the catfish protein). This protein was detected in nuclear extracts. cytoplasmic membrane preparations and cytosolic extracts of neutrophils and lymphocytes when reacted with mAbs C3-1 and 51A in an ELISA. However, the intensity of the reactions was dependent upon the cell type and cellular component. The putative cdr protein was not detected with any appreciable intensity in preparations from other cell types. This finding strongly suggests that this protein is expressed in a leukocyte-specific manner and is unique among the cdr group in that it is being expressed in a site that is not immune privileged.

Amino Acid Sequence↗

PubMedDate not supplied

Scaffold precoating with human autologous extracellular matrix for improved cell attachment in cardiovascular tissue engineering.

Cell attachment to a scaffold is a precondition for the development of bioengineered valves and vascular substitutes. This attachment is generally facilitated by the use of precoating factors, but some can cause toxic or immunologic side effects. Autologous extracellular matrix (ECM) is used as a precoating factor in our study. Ascending aortic tissue was cultured to obtain human myofibroblasts. Autologous ECM was extracted from the same aortic tissue. Poly(glycolic acid) (PGA) scaffolds were precoated with autologous ECM, human serum, or poly-L-lysine; the control group was pretreated with phosphate buffered saline (PBS). Myofibroblasts were seeded onto each scaffold, and the cell attachment was assayed and compared. Compared with the control group, precoating with human serum, poly-L-lysine, and ECM increased number of attached cells by 24%, 53%, and 48%, respectively. Differences between precoating groups were significant (p < 0.01), except for ECM versus poly-L-lysine. Scanning electron microscopy also demonstrated the high degree of cell attachment to the PGA fibers on scaffolds precoated with ECM and poly-L-lysine. Precoating polymeric scaffold with autologous human extracellular matrix is a very effective method of improving cell attachment in cardiovascular tissue engineering without the potential risk of immunologic reactions.

Aorta↗

PubMedDate not supplied

Approach to the mitral valve through a right thoracotomy in potentially hazardous reoperation.

BACKGROUND: Repeat sternotomy for mitral valve surgery may be hazardous in some patients. A right thoracotomy avoids the densely scarred area beneath the sternum and provides adequate in-line exposure of the mitral valve. METHODS: Between 1994 and 1997, five patients were reoperated for a mitral valve or prosthesis dysfunction through a right thoracotomy. Indications were three second redo-mitral valve surgeries and two first redo, once in a patient with an aortic prosthesis and once in a patient with patent aortocoronary grafts. The operation was performed without clamping the ascending aorta in moderate hypothermic (four patients) or normothermia (one patient). RESULTS: Exposure of the mitral valve for replacement (four patients) or for repair of a paraprosthetic leak (one patient) was optimal in all patients. Resumption of cardiac function occurred rapidly after repair without specific support. Postoperative course was uncomplicated. Blood loss ranged from 300 to 700 mL. Patients were discharged from 7 to 12 days postoperatively. They are in New York Heart Association (NYHA) functional Class I (four patients) and II (one patient), from 3 to 42 months postoperatively. CONCLUSION: Right thoracotomy provides a direct "in the line of vision" access to the mitral valve. Because complete de-airing of the heart is difficult and respiratory function depressed after a right thoracotomy, this approach seems suitable when technical difficulties are expected in sternal reopening.

Adult↗

PubMedDate not supplied

Tissue engineering of a bioprosthetic heart valve: stimulation of extracellular matrix assessed by hydroxyproline assay.

Creation of an autologous heart valve by tissue engineering offers a promising approach to cardiac surgery. Although we have demonstrated successful formation of native valve analogous tissue in vitro, hemodynamic competence remains a serious problem. The aim of this study was to optimize in vitro formation of collagen as a precondition for mechanical stability of new tissue. Human myofibroblasts were seeded on square sheets of biodegradable scaffolds (control). To stimulate collagen production, one series was cultured with L-ascorbic acid 2-phosphate. In a second series, the seeded scaffolds were subjected to tension by mounting them on a frame. After 4 weeks of culture time, the collagen content of the different series was assessed by hydroxyproline assay. Light and scanning electron microscopy were performed. Hydroxyproline content of the framed scaffolds was 10 times higher than that of the control group (p < 0.05) and 6 times higher than in the unframed scaffolds grown with ascorbic acid (p < 0.05), respectively. Scanning electron microscopy proved extensive formation of solid tissue in the framed samples. These results demonstrate that supplementation of myofibroblast cultures with ascorbic acid, especially if grown on strained scaffolds, significantly increases collagen content, which is crucial for mechanical stability. This concept is a further step toward the creation of a hemodynamically competent autologous heart valve.

Ascorbic Acid↗