BACKGROUND:Current cardiac bioprostheses and mechanical valves are shown to have some flaws and shortcomings, and tissue-engineered heart valves which can avoid these problems are becoming an ideal choice for valve replacement.
OBJECTIVE:To explore the experimental progress in the construction of tissue-engineered heart valves.
METHODS:Experimental studies related to tissue-engineered heart valves were retrieved in databases. Three main elements for tissue-engineered heart valves are seed cells, scaffold materials, and cellseeding.
RESULTS AND CONCLUSION:Cardiac valve repair and replacement is the primarily surgical treatment for valvular heart disease. At present, seed cells mainly for construction of tissue-engineered heart valves include vascular endothelial cells, endothelial progenitor cells and bone marrow mesenchymal stem cells. The acellular scaffold has good biomechanical properties and histocompatibility. After cellseeding, a continuous celllayer wil form on the scaffold surface, which makes it possible to construct tissue-engineered heart valves. Tissue-engineered heart valve has a good prospect, but it is stil in the early stage of research and there are stil many problems that need to be solved.

Using Mortierella isabellina as starting strain, mutagenized with UV,screened by selecting mutants resisting maleic hydrazide,a fatty acid dehydrogenase inhibitor, directly on gradient plate,a mutant M 80 overproducing Gamma Linolenic Acid (GLA) was obtained, which has much higher productive qualities than its parental strain Its dry cell weight reaches 25 10g/L,lipid yield 12 35g/L,and GLA yield 771 88mg/L

OBJECTIVETo identify and characterize laryngeal cancer related novel genes located on chromosome 6q25.

METHODSElectric hybridization was performed in human genome database using EST (expression sequence tag) as probe. Novel genes were deduced by software from positive DNA clones and their cDNAs were amplified by RT-PCR using primers designed according to the sequence of the putative genes.

RESULTSA novel gene was cloned successfully. The full length of this gene was about 21 kb. It contained two exons and produced a 1006 bp transcript coding a protein with 235 amino acid residues. It's 5'flanking sequence contained two binding sites of oncoprotein c-Myc, thus it was named MTLC (c-Myc target from laryngeal cancer cells). Homologous assay showed that MTLC exhibited little overall homology to known human proteins but it exhibited good overall homology to mouse MT-MC1 protein with an identity of 78%. The primary structure of MTLC protein contained a nuclear location signal motif, but it did not have other conserved domains. The results of subcellular location experiment showed that MTLC expressed in nuclei of human hepatocellular carcinoma cell line Bel7402 cells, while a wide distribution of MTLC in various tissues was demonstrated by Northern blotting.

CONCLUSIONMTLC may play an important role as a target gene of c-Myc and as a transcription factor in keeping the normal physiological process of cells.

Amino Acid Sequence ; Base Sequence ; Blotting, Northern ; Chromosomes, Human, Pair 6 ; genetics ; Cloning, Molecular ; DNA, Complementary ; chemistry ; genetics ; Gene Expression ; Green Fluorescent Proteins ; Humans ; Laryngeal Neoplasms ; genetics ; Luminescent Proteins ; genetics ; metabolism ; Microscopy, Fluorescence ; Molecular Sequence Data ; Nuclear Proteins ; genetics ; Recombinant Fusion Proteins ; genetics ; metabolism ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Tumor Cells, Cultured

BackgroundFunctional near-infrared spectroscopy （fNIRS） is a new generation of imaging tool that can be used to assist the diagnosis of psychiatric disorders. However， whether the patterns of prefrontal cortex activation observed by fNIRS are specific for different psychiatric disorders remains to be explored. ObjectiveTo investigate the characteristics of prefrontal cortex activation in patients with depression， anxiety disorder， bipolar disorder and schizophrenia in verbal fluency task （VFT） using fNIRS. MethodsFrom September to December 2021， 39 patients with schizophrenia， 205 patients with depressive disorder， 212 patients with anxiety disorder and 77 patients with bipolar disorder meeting the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） were recruited in the outpatient and inpatient department of West China Hospital， Sichuan University. fNIRS was used to monitor the prefrontal cortex hemodynamic changes of patients under VFT， and the clinical symptoms of patients were assessed by Symptom Checklist 90 （SCL-90） and Hypomania Checklist-32 items（HCL-32）. Differences in mean oxyhemoglobin （HbO₂） concentration and the initial slope from 2 to 7 second during VFT were compared among patients with different diseases， and the correlation between mean HbO₂ concentration/initial slope and clinical symptoms was analyzed by partial correlation analysis. ResultsThe concentration of HbO₂ in channel 4 （Z=2.828， P=0.028） and channel 6 （Z=2.912， P=0.022） in patients with depression were significantly higher than those in patients with schizophrenia. Patients with anxiety had significantly higher changes in mean HbO₂ concentration in channel 4 （Z=3.154， P=0.010）， channel 5 （Z=3.021， P=0.015）， channel 6 （Z=2.980， P=0.017） and of all channels （Z=2.881， P=0.024） than those of schizophrenia patients. There was a statistically significant difference in the initial slope of channel 3 between patients with depressive disorder and those with bipolar disorder （Z=2.691， P=0.039）. Among patients with bipolar disorder， the anger-hostility scores of SCL-90 were negatively correlated with the mean HbO₂ concentration changes in channel 4 （r=-0.505， P=0.004）， channel 6 （r=-0.390， P=0.004）， channel 15 （r=-0.546， P=0.002）， channel 16 （r=-0.550， P=0.002） and the mean HbO₂ concentration changes of all channels （r=-0.491， P=0.006）. ConclusionPatients with schizophrenia had lower activation in frontopolar and orbitofrontal region than patients with depression and anxiety disorder， and the initial slope of the right frontopolar， inferior frontal and orbitofrontal region in patients with depression is higher than patients with bipolar disorder. In addition， patients with bipolar disorder had less activation in the frontopolar and orbitofrontal lobe， the insular cover of Broca's area and the upper outer frontal cortex， and were more irritable and hostile. ［Funded by 1·3·5 Project for Disciplines of Excellence-Clinical Research Incubation Project， West China Hospital， Sichuan University （number， ZYJC21083）］