Biomedical subjects

L Liu

Publications and source records attributed to L Liu.

At least 433 records · Page 24Linked to original sources

PubMed2000

Inductive activity of recombinant human growth and differentiation factor-5.

Growth and differentiation factor-5 (GDF-5) is a divergent member of the transforming growth factor-beta/bone morphogenetic protein (BMP) superfamily that is required for proper skeletal patterning and development in the vertebrate limb. Based on the homology of GDF-5 with other bone-inducing BMP family members, the inductive activity of a recombinant form of human GDF-5 (rhGDF-5) was evaluated in a series of in vitro assays and in vivo bone-formation models. The in vitro response to rhGDF-5 resulted in the formation of chondrogenic nodules in fetal rat calvarial cells cultured in the context of collagen or collagen/hyaluronate extracellular matrices. Matrices loaded with rhGDF-5 induced ectopic cartilaginous and osseous tissue when implanted in subcutaneous or intramuscular sites. In non-human primate long-bone-defect and spinal-fusion models, rhGDF-5 combined with a mineralized collagen matrix induced bone formation in a manner equivalent to autogenous bone. These results highlight the unique potential of rhGDF-5 in a wide variety of orthopaedic applications.

Absorbable Implants↗

PubMed2000

The use of virtual reality in the assessment of driving performance in persons with brain injury.

In this article, we present the results of a pilot study that examined the driving performance of persons with brain injury using a virtual reality environment, known as the DriVR. Virtual driving performance was examined and compared to on-road, cognitive, visual-perceptual, and driving video test results. The DriVR appeared to be a useful adjunctive screening tool for assessing driving performance. However as with any new assessment tool, will need to undergo further empirical validation.

Automobile Driver Examination↗

PubMed2000

The mechanism of transport of the multitargeted antifolate (MTA) and its cross-resistance pattern in cells with markedly impaired transport of methotrexate.

MTA (LY231514) is an antifolate that targets multiple folate-dependent enzymes. In this report, MTA transport was characterized in wild-type L1210 cells and variants with impaired membrane transport or polyglutamation. MTA influx via the reduced folate carrier was somewhat faster (approximately 30%) than that for methotrexate (MTX). Unlike MTX, MTA was rapidly polyglutamated in L1210 cells; hence, a folylpoly-gamma-glutamate synthetase-deficient L1210 variant was used to assess net transport and efflux properties. The MTA transmembrane gradient for exchangeable drug was 2.5 times greater than the MTX gradient, attributable primarily to an efflux rate constant 40% that of MTX. No MTA was bound to dihydrofolate reductase. When grown with folic acid, MTX-resistant L1210 variants with mutations in the reduced folate carrier demonstrated cross-resistance to MTA, markedly reduced MTA accumulation, and only a slightly decreased intracellular folate cofactor pool as compared to L1210 cells. However, when 5-formyltetrahydrofolate was the growth substrate, these MTX-resistant cells were less resistant or negligibly resistant to MTA, accumulated more MTA, and had a lower folate pool as compared to L1210 cells. MTA activity and the intracellular folate pool in L1210 cells were inversely related. These data indicate that MTA polyglutamation in L1210 cells is favored by both the generation of high intracellular drug levels and high MTA affinity for FPGS relative to MTX. Cells resistant to MTX because of impaired transport may retain appreciable sensitivity to MTA because of a concurrent reduction in tetrahydrofolate cofactor transport resulting in cellular folate depletion, which diminishes endogenous folate suppression of MTA polyglutamation.

Animals↗

PubMed2000

[An experimental study on arsenic trioxide-selectively induced human hepatocarcinoma cell lines apoptosis and its related genes].

OBJECTIVE: To study the possible apoptosis-inducing effect of arsenic trioxide on human hepatocarcinoma (HCC) cells, and its molecular mechanisms. METHODS: Arsenic trioxide action on the cell growth, apoptosis, periodicity and the expression of related genes in two human hepatocarcinoma cell lines QGY-7701 and QGY-7703, and normal humanhepatic cell line L-02 in vitro was observed by MTT assay, acridine orange (AO) /ethidiumbromide (EB) fluorescent staining, electron microscopy detection, DNA gel electrophoresis, flow cytometry, TUNEL assay and immunohistochemical staining. RESULTS: Arsenic trioxide could strongly inhibit the growth of human hepatocarcinoma cells QGY-7701 and QGY-7703 with the cell cycle arrested on S phase, and induce the apoptosis of the cells with bcl-2 gene expression down-regulated and bax and Fas gene expression up-regulated. But arsenic trioxide had no obvious effect on the normal hepatic cells. CONCLUSION: Arsenic trioxide has significant selective apoptosis-inducing effect on the human hepatocarcinoma cells, which is regulated by several genes. The results provide the credible experimental basis for clinically treating HCC with arsenic trioxide.

Antineoplastic Agents↗

PubMed2000

[The effect of polylactide screws on fracture healing].

This experiment aimed at investigating the effect of a kind of home-bred poly-DL-lactide screws on fracture healing. An operation was performed so as to make bilateral lateral condylar fractures of the femur in 8 dogs. The left sides were fixed with 2 home-bred PDLLA(Mv = 43 x 10(4)) screws, and the contralateral sides were fixed with 2 metalic screws to be used as controls. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery. Optic microscopy and SEM photography were done. The results of optic microscopy showed that fibrous callus formed already in both groups by 2 weeks after surgery, and bilateral fractures united uneventfully by 12 weeks. Although the course of fracture healing in experimental group was slower than that in control group, the osteogenesis in experimental group appeared to be normal. The SEM examination demonstrated that collagenous fibers arranged regularly and calcified normally in both groups at 12 weeks. And many square and rhomboid granules produced from the degradation of PDLLA material were found in experimental group at 12 weeks. Therefore, it is suggested that this kind of home-bred PDLLA screws should be applicable to fractures where the tissues are rich in blood supply.

Animals↗

PubMed2000

[Analysis of phenylethanoid glycosides in the extract of herba Cistanchis by LC/ESI-MS/MS].

AIM: To analyze the phenylethanoid glycosides in Cistanche deserticola Y. D. Ma and its alternatives. METHODS: An HPLC/MS/MS method has been developed for the analysis of seven kinds of phenylethanoid glycosides in Cistanche deserticola Y. D. Ma, C. salsa (C. A. Mey) G. Beck and C. tubulosa (Schenk) R. Wight. The [M - H]- ions were observed for five standards and Cistanche extracts. The glycosidic linkages, the core, and the attached sugar (s) of the phenylethanoid glycosides can be determined from the collision-induced dissociation spectra of the molecular. RESULTS: Seven kinds of phenylethanoid glycosides (echinacoside, acteoside, cisacteoside, isoacteoside, 2'-acetylacteoside, cistanoside A, osmanthuside B) in Cistanche deserticola Y. D. Ma, six kinds (echinacoside, acteoside, cisacteoside, isoacteoside, 2'-acetylacteoside and cistanoside A) in C. salsa (C. A. Mey) G. Beck and five kinds (echinacoside, acteoside, cisacteoside, isoacteoside and 2'-acetylacteoside) in C. tubulosa (Schenk) R. Wight were detected. CONCLUSION: The difference of the relative distribution of these phenylethanoid glycosides in each extract was found out. Phenylethanoid glycosides are the specific constituents in Cistanchis, which can be used to distinguish different species in Genus Cistanchis.

Drugs, Chinese Herbal↗

PubMed2000

[Detection for anti-Hantavirus IgM in patient serum with silver enhanced dot immunogold filtration assay].

OBJECTIVE: To establish a more rapid and simple method for detecting anti-Hantavirus IgM in patient' s serum. METHODS: A silver enhanced dot immunogold filtration assay (SEDIGFA) was developed by coating the nucleocapsid protein of Hantavirus on nitrocellulose (NC) membrane, adding colloidal gold labeled sheep anti-human IgM antibody and the silver enhancer. The whole procedure can be finished within 10 minutes. RESULTS: The coincidence rate of the results of serum samples simultaneously operated with ELISA and SEDEIGFA was 98% for anti-Hantavirus IgM. CONCLUSIONS: SEDIGFA is more simple and rapid for application to small medical laboratories. It can be applied for early diagnosis of hemorrhagic fever with renal syndrome (HFRS).

Gold Colloid↗

PubMed2000

[Skin sparing incision mastectomy and immediate TRAM flap breast reconstruction].

OBJECTIVE: In order to achieve a high-quality reconstructed breast, we improved the operation method using the skin sparing incision mastectomy and immediate TRAM flap breast reconstruction. METHODS: Patients with duct carcinoma in situ were selected to undergo mastectomy with a skin sparing incision. The site of the previous biopsy incision was marked around the areola, and then the preferred skin sparing incision included the nipple-areola complex and a margin around the biopsy site for the non-ptotic breast. The excised skin was replaced as precisely as possible with the TRAM flap skin immediately. While the mastectomy was being performed the TRAM flap was incised and elevated. The pedicled or free TRAM flap has been used for 34 patients. Nipple-areola reconstruction was made at the second stage. RESULTS: The results of the skin sparing breast reconstruction are better than other breast reconstruction techniques in the breast's shape, colour, sensation, symmetry and incision scar. CONCLUSIONS: Skin sparing incision mastectomy with immediate TRAM flap breast reconstruction technique is an ideal breast reconstructive method for the patients with breast duct carcinoma in situ. The advantages of the method include 1. The TRAM flap is an autograft without rejection; 2. The reconstructed breast has good shape and better sensation than other autograft reconstructive techniques since most breast skin has been spared; 3. The symmetry of the reconstructed breast with the contralateral breast is improved.

Adult↗

PubMed2000

Public pension reform in Japan.

The March 2000 pension reform in Japan focused on the long-term financial sustainability of the country's two-tiered public pension system. The government opted for incremental changes in order to maintain pension solvency through 2060. Those changes could reduce future pension funding liability by an estimated one-third. Further, the decision to avoid structural reforms of its pension programs was based on fiscal considerations. Expanding general revenue funding for the first tier from the current share of one-third to cover the entire cost would require increases in the consumption tax that proved to be politically unacceptable. Fully privatizing the second, earnings-related tier would entail transition costs too great to bear at a time of rising budget deficits. In addition, the Japanese public generally supported the sharing of financial burden for public pension programs through a combination of benefit cuts, a raise in the pensionable age, and contribution rate increases. If current cost projections prove to be inaccurate, future pension reviews (scheduled every 5 years) will give the government further opportunity to fine-tune program changes.

Aged↗

PubMed2000

Different Wnt-5A gene expressions in the renal cell carcinoma GRC-1 cell line during the cell cycle.

OBJECTIVE: To investigate the gene expression at transcription level of growth factor Wnt-5A in different phase during the cell cycle. METHODS: We synchronized the renal cell carcinoma GRC-1 cell line by double thymidine blocks and high-pressure N2O gae methods and amplified Wnt-5A cDNAs from different phase using Semi-quantitative RT-PCR (reverse transcriptase polymerase chain reaction). The PCR products were electrophoresized on the agrose gel and detected by Gel Doc 1000 computer controlled system integrating the volumes of each band, representing the intensities of all pixels in a defined band. RESULTS: The different mRNA expressions of growth factor Wnt-5A was detected in RCC GRC-1 cell line. In S phase, the highest level of Wnt-5A transcript was observed, and in G1 and M phase, medial and lowest, respectively. The differences between S and M stages were statistically significant (P < 0.05). CONCLUSION: Growth factor Wnt-5A has the potential effect on tumorigenesis. It contributes to all phases during cell cycle but in S phase especially.

Carcinoma, Renal Cell↗

PubMed2000

Embolic events in 93 elderly Chinese patients with atrial fibrillation.

OBJECTIVES: To evaluate the prevalence of embolic events and relevant factors in elderly Chinese patients with atrial fibrillation(AF), and to provide evidence on ways to prevent embolic events. METHODS: Autopsy data from ninety-three continous elderly Chinese patients with AF were analysed. The incidence of embolic events and its relationship to underlying disease, pathologic changes in the heart, and other clinical characteristics were examined. RESULTS: Embolism were observed in 27 of 93 cases, with an incidence of 29.03%. The incidence of embolic events was higher in elderly patients with rheumatic heart disease than those with coronary artery disease, hypertensive myocardiopathy and heart diseases. Patients with chronic AF, with a course of AF > or = 3 years, and those with heart failure or diabetes had a higher incidence of embolic events than those without these complications. There was significant difference in incidence between paroxysmal and chronic AF. Patients with left atrial or ventricular enlargement, mural thrombosis in cardiac chambers, valvular calcification and valvular vegetation also had a higher incidence of embolic events. Oral dipyridamole (75-150 mg/d) or aspirin (50-150 mg/d) showed no definite effects in preventing embolism in some patients. CONCLUSIONS: There was a high incidence of embolic events in elderly Chinese patients with AF. Anticoagulation therapy should be provided to the elderly patients with AF, especially to the patients with risk factors for embolism.

Aged↗

PubMed2000

Mitochondrial gene variation in type 2 diabetes mellitus: detection of a novel mutation associated with maternally inherited diabetes in a Chinese family.

OBJECTIVE: To explore the relationship between type 2 diabetes mellitus and the mutation(s) in mitochondrial DNA. METHODS: According to the previous literature, the fragment of mitochondrial DNA from nucleotide 3153 to 3551, which had shown high frequency of point mutation, was scanned with the technique of polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) in Chinese normal control, type 2 diabetic population, and 12 families suffered from maternally inherited type 2 diabetes mellitus. Direct sequencing was applied to detect the fragments with abnormal conformation. RESULTS: No special band was found in SSCP electrophoreses in Chinese normal control, and only one subject (No. 81) of diabetic population indicated the abnormality in SSCP study, which was affirmed to be a silent point mutation of T to C at nucleotide 3336 inducing no change in amino acid (ATT-->ATC, Ile). Pedigree 25,001 was the only family that exhibited strongly different SSCP characteristic from the other 11 ones, which was confirmed to be caused by a single point mutation mt3285T-->C/T in the coding region of tRNA(Leu(UUR)) gene by the technique of direct sequencing. CONCLUSIONS: The variation within mt DNA 3153-3551 is not the major cause of type 2 diabetes in Chinese population suffered from this disease in this study. The point mutation T-->C/T at the mitochondrial nucleotide 3285, which was found in pedigree 25,001, is located in the highly conservative region of tRNA(Leu(UUR)) gene. It is strongly suggested that this mutation cause the conversion in the 3-dimentional structure of tRNA(Leu(UUR)), which might disturb the normal translation and lead to the impairment in mitochondrial oxidative phosphorylation characterized by the defects of the polypeptides involved in the respiratory chain. Thus, insulin secretion deficiency and insulin resistance might occur.

Adult↗

PubMed2000

[Influence of sonographic examination on embryo villi during early pregnancy].

OBJECTIVE: To evaluate the effects of sonographic examination on embryo villi during early pregnancy. METHODS: Eighty early pregnant women intended for artificial abortion were divided into 4 groups: group I served as control, the remaining 3 groups underwent pelvic sonographic examination transabdominally for 10 minutes (group II), transvaginally for 3 minutes (group III) or for 10 minutes (group IV) respectively. After 1 hour embryo villi were obtained through artificial abortion and examined by electronic microscopy, biochemical methods and sister chromatid exchanges (SCE). RESULTS: In group IV, but not group II, III, the embryo microvilli were found broken, lost and disarranged. The rough endoplasmic reticulum of trophoblasts expanded. Their malondial dehyde levels increased while the superoxide dismutase (SOD) decreased as compared with control (P < 0.01). There was no difference of SCE among these 4 groups. CONCLUSION: It is recommended that sonographic examination should be done through abdominal approach for shorter than 10 minutes during early stage of pregnancy.

Adult↗

PubMed2000

[Changes on the protein kinase C activity of alveolar macrophages in patients with idiopathic pulmonary fibrosis].

OBJECTIVE: To study the changes on protein kinase C(PKC) activity of alveolar macrophages (AM) in patients with idiopathic pulmonary fibrosis(IPF). METHOD: The PKC activity of AM in 9 healthy volunteers and 15 patients with IPF was investigated by radioactivity measuring. RESULTS: The total, cytosolic and particulate fraction PKC activity of AM in bronchoalveolar lavage fluid(BALF) from patients with IPF were higher than those from control group(P < 0.01 and P < 0.05). The total and the membrane fraction PKC activity had positive correlation with the number of cells in BALF(r = 0.8135, P < 0.01 and r = 0.5917, P < 0.05) respectively. CONCLUSION: As a bypass of transmembrane signal transduction, PKC was suggested to be involved in the development of IPF.

Adult↗

PubMed2000

[Pleural effusion of gout].

OBJECTIVE: To investigate the lung complication of patients with gout. METHODS: Laboratory, radiation and pathology examining were exerted to 11 patients with gout and lung injury. RESULTS: Uric acid crystal was found in four patients pleural effusion and stones in two patients' spittle which were consist of monosodium urate (MSU). Uric acid salt crystal was found sputum in five patients as well as fibrosis was found in the patients' lung by radiation and pathology examination. CONCLUSIONS: The diagnoses of lung complications in eleven patients with gout were reliable.

Adult↗

PubMed2000

[Ifosfamide combination chemotherapy for advanced gynecologic malignancies].

OBJECTIVE: To evaluate the clinical efficacy and toxicity of ifosfamide (IFO) combination chemotherapy in patients with advanced gynecologic malignancies. METHODS: Thirty-four patients with gynecologic malignancies were included in this series. Of the 34 patients, 26 with epithelial cancer of the ovary were previously treated with cisplatin-containing combination chemotherapy but failed to respond or recurred after treatment. They were treated with IEP (IFO, VP16, PDD) regimen. The remaining 8 patients with uterine sarcoma (5 cases), squamous-cell carcinoma of the uterine cervix with metastases to the liver or bone (2 cases), and endometrial carcinoma with lung metastases (1 case) were treated with IFO combination chemotherapy. At least two courses of treatment were given unless tumor progression occurred after the first course. RESULTS: The overall response rate was 35.3% including 8.8% complete response. The response rate of 26 patients with ovarian cancer was 30.8%. Two patients with PDD-sensitive tumor all achieved complete response, which lasted for one year. The response rate of the remaining 24 PDD-resistant patients was 25% with a mean duration of 5.5 months. There was no complete response. Two patients with cervical carcinoma and two of five patients with uterine sarcoma responded to IFO combination chemotherapy. Relatively severe hematological toxicity was observed, including grade III and IV leucopoenia and thrombocytopenia. Two patients died from severe toxicity. CONCLUSION: IFO combination chemotherapy is effective in treating recurrent or progressive gynecologic malignancies, especially PDD-sensitive ones. Myelosuppression is relatively severe which may be due to prior long term and intensive chemotherapy.

Adult↗

PubMed2000

[Expression of Fas ligand in urogenital malignant cell lines and renal cell carcinoma].

OBJECTIVE: To explore the expression of Fas ligand in urogenital malignant cell lines and renal cell carcinoma. METHODS: With immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR), we detected the expression of Fas ligand (FasL) in 6 urogenital malignant cell lines, bladder carcinoma cell lines (T(24), EJ, BIU-87), renal cell carcinoma cell lines (GRC-1, RCC-949), prostatic carcinoma cell line (PC-3M), and 10 cases of renal cell carcinoma. RESULTS: The expression of FasL was detected in 3 (BIU-87, RCC-949, GRC-1) of the 6 urogenital malignant cell lines with immunocytochemistry, and 4 (BIU-87, RCC-949, GRC-1, PC-3M) of 6 urogenital malignant cell lines with RT-PCR method. No expression of FasL was detected in bladder carcinoma cell lines T(24) and EJ. Eight of 10 renal cell carcinoma tissues positively expressed FasL mRNA. CONCLUSIONS: FasL can express in urogenital malignant cell lines and renal cell carcinoma.

Carcinoma, Renal Cell↗

PubMed2000

[Ultrasound biomicroscopic examination of secondary pupillary block glaucoma].

OBJECTIVE: To study the imaging characteristics of ultrasound biomicroscopy of secondary pupillary block glaucoma. METHODS: 11 cases with pupillary block glaucoma diagnosed by ultrasound biomicroscopy were studied which had been suspected as malignant glaucoma at the beginning. RESULTS: There were no obviously typical characteristics of pupillary block glaucoma shown in the images of ultrasound biomicroscopy in these cases. However, the existence of posterior chamber in each case strongly supported the diagnosis of pupillary block glaucoma. The imaging characteristics of ultrasound biomicroscopy were different in terms of the different primary disorders which resulted in the pupillary block glaucoma including iridocyclitis, lens subluxation resulted from trauma and glaucoma filtration surgery. In the cases of lens subluxation, the main characteristic was the increase of the distance between the lens and the ciliary process at the site of subluxation and the lens forward movement. In the cases of iridocyclitis, anterior and posterior synechiae were the main characteristics. And in the cases of glaucoma filtration surgery there were two main characteristics. One was that the distance between the ciliary process and the equator of lens existed obviously, and the other was the occlusion of the inner ostium of glaucoma filtration surgery or peripheral iridectomy. CONCLUSION: Ultrasound biomicroscopy (UBM) has important value in the diagnosis of secondary pupillary block glaucoma and the differentiation between it and malignant glaucoma. Whether the posterior chamber exists or not is the differential point between the pupillary block glaucoma and the malignant glaucoma.

Adult↗