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Biomedical subjects

T L Liu

Publications and source records attributed to T L Liu.

At least 19 recordsLinked to original sources
PubMed2006

Expression and localization of recombinant human B2 receptors in the methylotrophic yeast Pichia pastoris.

The human bradykinin B2 receptor (B2R) fused with green fluorescent protein (GFP) at the C-terminal has been expressed in the methylotrophic yeast of Pichia pastoris. In the expression vector, B2R gene was drove under the highly inducible promoter of alcohol oxidase 1 gene of P. pastoris. By fluorescence activated cell sorting (FACS) analysis and western blot analysis, it was proved that B2R recombinant receptor proteins were expressed at high level in the yeast. Further more, the transformants of P. pastoris were monitored with confocal microscopy, a strong green fluorescence was checked out. The recombinant B2R receptor proteins were mainly located on the plasma membrane proved by immunofluorescence microscopy.

Cell Membrane↗
PubMed2006

How to map ses, a mutant of Arabidopsis thaliana affecting pollen development.

In Arabidopsis, map-based cloning has been developed to an effective method in mutant genetic analysis because high-density markers are available, candidate genes or genomic sequences can be amplified by PCR and transgenic techniques are simplified. Mutant ses named from shortened early-stage siliques was used as an example to show how to map a mutant in this day. By the process of bulked segregants analysis, linkage testing, large-scale and fine scale mapping, mutant ses was narrowed into a 67 kb interval from CER448792 (2000541 bp) to CER464544 (2067844 bp) crossing over the right of BAC F12K11 to the left of the BAC F4H5 including at most 22 putative genes on the top of chromosome l. In sequence-based map of Arabidopsis genes with Mutant phenotype (SMAGMP) mutant ses was between ATlg06150 (EMB1444) and ATlg08060 (MOM). The SES mapping also showed that developed markers on polymorphism site of CAPC not only were simplified and but worked well. 24 markers from CAPC used in the mapping maybe help Arabidopsis researches with others and the methods related to SES mapping also gave an example of positional cloning.

Arabidopsis↗
PubMed2001

Preclinical study of adenoviral p53 gene therapy for esophageal cancer.

An alteration of the p53 gene function is a major factor in the development of esophageal cancer. Recently, p53 gene therapy has been applied for clinical studies in lung cancer and head and neck cancer. However, no preclinical studies have yet demonstrated an anticancer effect of adenoviral-mediated wild-type p53 gene therapy on esophageal cancer. We herein evaluated the effect of p53 adenoviral gene therapy on human esophageal squamous cell carcinoma to test the ability of clinical application. A normal esophageal epithelial cell line (EN53F) and two human esophageal cancer cell lines (ECGI-10 and T.Tn) with a p53 alteration were used. The transduction efficiency, p53 protein expression, p21 protein expression, the induction of apoptosis, and growth suppression were assessed by using the recombinant adenoviral vector Ad5CMV-p53. The transduction efficiency was 60%-80% at 100 plaque-forming units (PFU)/cell and 80%-100% at 300PFU/cell. A significant growth suppression following an Ad5CMV-p53 infection was observed in both cancer cell lines. A Western blot analysis confirmed the presence of both exogenous p53 protein expression and p21 protein induction. Apoptotic cell death was observed with TUNEL staining. T.Tn xenografts in nude mice transduced with Ad5CMV-p53 demonstrated significant growth suppression. These data suggest that Ad5CMV-p53 may thus be a potentially effective therapeutic agent for locally advanced esophageal cancer.

Adenoviruses, Human↗
PubMed2000

Identification and genetic mapping of four novel genes that regulate leaf development in Arabidopsis.

Molecular and genetic characterizations of mutants have led to a better understanding of many developmental processes in the model system Arabidopsis thaliana. However, the leaf development that is specific to plants has been little studied. With the aim of contributing to the genetic dissection of leaf development, we have performed a large-scare screening for mutants with abnormal leaves. Among a great number of leaf mutants we have generated by T-DNA and transposon tagging and ethyl-methae sulfonate (EMS) mutagenesis, four independent mutant lines have been identified and studied genetically. Phenotypes of these mutant lines represent the defects of four novel nuclear genes designated LL1 (LOTUS LEAF 1), LL2 (LOTUS LEAF 2), URO (UPRIGHT ROSETTE). and EIL (ENVIRONMENT CONDITION INDUCED LESION). The phenotypic analysis indicates that these genes play important roles during leaf development. For the further genetic analysis of these genes and the map-based cloning of LL1 and LL2, we have mapped these genes to chromosome regions with an efficient and rapid mapping method.

Arabidopsis↗
PubMed1994

[The clinical practice of video-assisted thoracic surgery (VATS)].

From November 1992 to March 1994, thirty five patients were performed using VATS in our hospital. The procedures included blebectomy with pleurodesis 14 cases; wedge resection 10 cases; malignant pleural effusion, pleural biopsy and pleurodesis 4 cases; pleural biopsy 3 cases; lung tumor biopsy 2 cases; lung biopsy 2 cases. Converted into thoracotomy 2 cases because of the tumors could not be resected thoracoscopically. No death and severe complication. The procedures were successful for diagnosis and treatment in our series. Compared with standard thoracotomy, the operative trauma, postoperative pain, drainage volume, tube time, postoperative hospitalization were remarkably less in this group (P < 0.05).

Adolescent↗
PubMed1994

[Thoracoscopy for the treatment of spontaneous pneumothorax].

Video-assisted thoracoscopy has used for lots of thoracic disorders. Spontaneous pneumothorax may be ideally suited for thoracoscopic management. Stapling of apical blebs and pleurodesis can now be performed thoracoscopically. We compared our results with thoracoscopic management of spontaneous pneumothorax in 12 patients (group I) with a group of 8 patients (group II) previously subjected to lateral thoracotomy. Operative time and hospital stay were less in group I (P < 0.05), as the use of parenteral narcotics after 24 hours (P < 0.05). There have been no recurrences to date in group I. Video-assisted thoracoscopic management is safe and offers the benefits of shorter hospital stays and less pain.

Adolescent↗
PubMed1994

[Management of pleural adhesion in the video-assisted thoracoscopic surgery].

This article describes the pleural adhesion managements in the video-assisted thoracoscopic surgery (VATS). We have operated the VATS successfully and developed a new technique for management of diffuse cellulose symphysis. We used this technique in 3 patients for treatment of lung diseases. No death and no complications occurred. Comparing with control group, the chest tube drainage time and hospital stay are not significant difference.

Adolescent↗
PubMed1994

[Video-assisted thoracoscopic surgery for pulmonary wedge resection].

Video-assisted thoracoscopic surgery (VATS) wedge resection of lung has largely become a practical surgical procedure because the development of instruments and surgical techniques. The safety and feasibility are more remarkable comparing with standard surgical procedure. From November, 1992 to March, 1994, twelve patients suffering from pulmonary mass were underwent VATS. VATS wedge resection in 10, VATS pulmonary mass biopsy in 2. No operative death and severe complications occurred in this group. We discussed the clinical classification, indication and the surgical technique in this paper.

Adult↗
PubMed1994

Small cell carcinoma of the lung in a patient with rheumatoid arthritis: a case report.

We describe an occurrence of small cell carcinoma of the lung in a 37-year-old woman with rheumatoid arthritis who did not receive any kind of cytotoxic agents for the rheumatic condition. There seemed to have no predisposing factor for the development of malignancy. The diagnosis of small cell carcinoma was based on repeated hemoptysis and cytologic finding of a rapidly growing mass over the forehead. The patient responded dramatically to chemotherapy with rapid resolution of forehead mass, relief of arthritis in the hands, and decrease of serum rheumatoid factor from 4800U/ml to 1200U/ml. This appeared to be the first report of small cell carcinoma of the lung developing in a patient with rheumatoid arthritis.

Adult↗
PubMed1994

Comparative experimental study between retrograde cerebral perfusion and circulatory arrest.

To evaluate the efficacy of retrograde cerebral perfusion in protecting the brain, we comparatively studied retrograde cerebral perfusion and total circulatory arrest in 18 hypothermic (20 degrees C) mongrel dogs (retrograde cerebral perfusion, n = 10; total circulatory arrest, n = 8). Retrograde cerebral perfusion was performed, maintaining an external jugular venous pressure of 25 mm Hg for 60 minutes. Retrograde cerebral perfusion provided half the cerebral blood flow and a third of the oxygen that was supplied during hypothermic cardiopulmonary bypass, which had a flow rate of 100 ml/min per kilogram. Oxygen consumption and carbon dioxide exudation did not increase on resuming cardiopulmonary bypass after retrograde cerebral perfusion, whereas they increased after total circulatory arrest (oxygen consumption 10.7 +/- 5.3 versus 19.1 +/- 8.6 ml/min, p < 0.05; carbon dioxide exudation, 0.92 +/- 0.54 versus 1.64 +/- 0.78 mmol/min, p < 0.05). Therefore, oxygen debt during retrograde cerebral perfusion was smaller than during total circulatory arrest. Retrograde cerebral perfusion also cooled the brain better than did total circulatory arrest (20.4 degrees +/- 1.5 degrees C versus 22.7 degrees +/- 0.7 degrees C, p < 0.01). Cerebral tissue oxygen tension decreased slightly (27.5 +/- 7.7 versus 12.3 +/- 3.0 mm Hg, p < 0.01), and cerebral tissue carbon dioxide tension increased slowly during retrograde cerebral perfusion (95 +/- 34 versus 147 +/- 44 mm Hg, p < 0.05). These changes were smaller than those seen in total circulatory arrest. Tissue concentrations of adenosine triphosphate in the brain remained relatively high during retrograde cerebral perfusion but decreased rapidly during total circulatory arrest (0.49 +/- 0.16 versus 0.21 +/- 0.05 mmol/gm, p < 0.01, just before resuming cardiopulmonary bypass). Retrograde cerebral perfusion cannot maintain aerobic metabolism but may reduce ischemic damage of the brain and may safely extend the cerebral circulation interruption time.

Adenosine Triphosphate↗
PubMed1994

Determination of optimum retrograde cerebral perfusion conditions.

Retrograde cerebral perfusion through a superior vena caval cannula is a new technique used to protect the brain during operations on the aortic arch. We measured cerebral tissue blood flow, oxygen consumption, and cerebrospinal fluid pressure under various perfusion conditions in hypothermic (20 degrees C) mongrel dogs (n = 18, 12.8 +/- 0.6 kg) to determine the optimum conditions for retrograde cerebral perfusion. Retrograde cerebral perfusion was performed by infusion via the superior vena caval cannula and drainage via the ascending aortic cannula while the inferior vena cava and azygos vein were clamped. Retrograde cerebral perfusion was performed as the external jugular venous pressure was changed from 15 to 35 mm Hg in increments of 5 mm Hg. Cerebral tissue blood flow was measured by the hydrogen clearance method. Hypothermic retrograde cerebral perfusion with an external jugular venous pressure of 25 mm Hg provided about half the cerebral tissue blood flow of hypothermic (20 degrees C) cardiopulmonary bypass with a flow rate of 1000 ml/min (13.7 +/- 7.9 versus 32.7 +/- 8.5 ml/min per 100 gm). It decreased significantly as the external jugular venous pressure was decreased from 25 to 15 mm Hg but did not increase significantly as the external jugular venous pressure was increased from 25 to 35 mm Hg. Whole-body oxygen consumption during hypothermic retrograde cerebral perfusion with an external jugular venous pressure of 25 mm Hg was one quarter of that during hypothermic cardiopulmonary bypass (3.4 +/- 0.7 versus 12.7 +/- 5.6 ml/min) and varied in proportion to external jugular venous pressure. The cerebrospinal fluid pressure was a little lower than the external jugular venous pressure (19.2 +/- 4.5 mm Hg versus 24.8 +/- 2.4 mm Hg) but also varied with the external jugular venous pressure. The cerebrospinal fluid pressure remained lower than 25 mm Hg so long as the external jugular venous pressure remained lower than 25 mm Hg. High external jugular venous pressure was associated with high intracranial pressure, which restricts cerebral tissue blood flow and may cause brain edema. We believe that a venous pressure of 25 mm Hg is the optimum condition for retrograde cerebral perfusion.

Animals↗
PubMed1988

Effects of short-term dietary restriction on survival of mammary ascites tumor-bearing rats.

We studied the effects of short-term dietary restriction on the survival of 3-4-month-old tumor-free and tumor-bearing Fisher rats. The diet-restricted food regimen consisted of alternate day ad libitum feeding followed by alternate day fasting. Diet-unrestricted control rats were fed ad libitum daily. Six tumor-free rats on the diet-restricted regimen compensated for the dietary restriction by an increase in food consumption during the alternate feeding days, and lost an average of only 2-3% of their weight in 13 days. Six tumor-free rats on a daily ad libitum feeding regimen gained an average of 6.8% in 15 days. The above dietary-restricted regimen was initiated 1 week before 24 rats were inoculated intraperitoneally with 15 million Mat 13762 ascites tumor cells. Sixteen of 24 (66.7%) diet-restricted tumor-bearing hosts and 5/24 (20.8%) diet-unrestricted tumor-bearing hosts survived at 9 days after tumor inoculation (p less than 0.005). Twelve of 24 (50%) diet-restricted tumor-bearing hosts, and 3 of 24 (12.5%) diet-unrestricted tumor-bearing hosts, survived at 10 days after tumor inoculation (p less than 0.025). Thus, the survival of tumor-bearing rats was enhanced by short-term relatively mild dietary restrictions. We suggest that relatively mild dietary restrictions should be included in clinical trials designed to inhibit cancer growth and enhance the survival of human cancer patients.

Animals↗
PubMed1987

Cytotoxic effects of free fatty acids on ascites tumor cells.

The effect of physiologic common free fatty acids (FFAs) on Mat 1376b ascites tumor cells in vitro and in vivo in F344 rats was investigated. Unsaturated fatty acids, such as palmitoleic (16:1), oleic (18:1), linoleic (18:2), linolenic (18:3), and arachidonic (20:4) acids, were significantly more effective killers of tumor cells in vitro than the corresponding saturated fatty acids of the same carbon length, including palmitic (16:0), stearic (18:0), and arachidic (20:0) acids. The saturated 16-carbon fatty acid (palmitic acid) was more toxic to tumor cells in vitro than the saturated 18-carbon (stearic) and 20-carbon (arachidic) acids. Injections of linoleic (18:2)-linolenic (18:3) acid combinations into rats inoculated with the tumor significantly enhanced the survival of the tumor-bearing animals. These results suggest that natural FFAs may under certain conditions be utilized as effective anticancer agents.

Animals↗