Biomedical subjects

Y Jin

Publications and source records attributed to Y Jin.

At least 127 records · Page 7Linked to original sources

PubMed2001

[Effect of exogenous p16 gene on biological behaviors of human lung cancer].

OBJECTIVE: To evaluate the biological effects of tumor suppressor gene p16 on human lung cancer cells with p16 gene deletion. METHODS: p16-pcDNA3 was transfected into lung cancer cell line A549 using lipofectin, in which p16 gene was homozygously deleted. Biological behaviors of the transfected cell line were investigated both in vitro and in vivo. The expressions of p16 mRNA and protein were detected by RT-PCR and immunohistochemistry. RESULTS: There was stable expression of p16 in the transfected cell line A549. Exogenous p16 gene significantly slowed down the growth of A549 cells as compared with the control. Flow Cytometry showed that the transfected cells were stagnated in G1 phage of cell cycle accompanying with apoptosis. In addition, clonogenic assay showed that the number of colony in soft agar was decreased in transfected cells as well. In vivo, a suppressed tumorigenicity and significantly decreased growth rate were shown in nude mice injected with A549 cells transfected with p16-pcDNA3, as compared with those in mice injected with either original A549 or A549 transfected with pcDNA3. CONCLUSION: Exogenous p16 gene can express stably in human lung cancer A549 cell line; exogenous p16 gene transfection induces apoptosis in lung cancer cells with p16 deletion and inhibits growth of the tumor in nude mice.

Animals↗

PubMed2001

[Influence of suppressor gene p16 on retinoic acid inducing lung cancer cell A549 differentiation].

OBJECTIVE: To investigate the role of suppressor gene p16 in the process of differential regulation of retinoic acid (RA) on the A549 lung cancer cells. METHODS: Tumor suppressor gene p16 was transfered into A549 cells and the cells were treated with all-trans retinoic acid (ATRA) at the dosage of 5 x 10(-6) mol/L for 4 d. After that, the proliferation and differentiation of A549 cells were examined by growth curve and cytometry analysis, the change of lung lineage-specific marker MUC1 was tested by immunohistochemical staining. Meanwhile, Western blot was used to observe the change of p16 protein expression in A549 cells treated with ATRA. RESULTS: ATRA could obviously inhibit the growth and induce the differentiation of A549 cells that were transfered with p16 gene. There were more cells arrested in G1/G0 phase and the expression of MUC1 was markedly down-regulated than in control cells. The expression of p16 protein was up-regulated in A549 cells treated with ATRA. CONCLUSION: Suppressor gene p16 could enhance the effects of RA on proliferative suppression and differential induction of A549 cells.

Antineoplastic Agents↗

PubMed2001

[Influence of fluid shear stress on the expression of monocyte chemotactic protein-1 by vascular endothelial cells].

OBJECTIVE: To study the effect of fluid shear stress on the expression of monocyte chemotactic protein-1(MCP-1) by vascular endothelial cells and its role in the early stages of atherogenesis(AS). METHODS: Parallel plate flow chamber was used to expose vascular endothelial cells to different shear stress. Sandwich ELISA (enzyme-linked immunosorbent assay) and RT-PCR (reverse transcription polymerase chain reaction) were applied to detect MCP-1 protein and mRNA respectively. RESULTS: Under 0.72 Pa shear stress, MCP-1 mRNA expression in endothelial cells reached a high level in 5 hours, but decreased to below the control level (P < 0.001) after 12 hours. The expression of MCP-1 mRNA showed a time dependent increase, which became slower 5 hours later. When different shear stress (0.30, 0.72, 2.40 Pa) was loaded for the same period of time (5 h), MCP-1 increased to above twice the control level, while its mRNA expression increased threefold as compared to the static control. CONCLUSIONS: The expression of MCP-1 reacts strongly to fluid shear stress. The steady laminar flow down regulates the gene expression of MCP-1. These results may help to explain why AS lesions tends to occur at the site of turbulent blood flow.

Cells, Cultured↗

PubMed2001

Reversing drug resistance in the ovarian carcinoma cell line SKOV3/mdr1 in vitro by antisense oligodeoxynucleotides.

OBJECTIVE: To investigate the effect of multidrug resistance gene 1 (mdr1) antisense oligodeoxynucleotides (ODNs) on reversing multidrug resistance in the drug resistant ovarian carcinoma cell line SKOV3/mdr1. METHODS: The ovarian carcinoma cell line SKOV3 transducted with a human multidrug resistance gene (mdr1) served as the drug resistant model (SKOV3/mdr1). The mdr1 antisense ODNs was transfected into SKOV3/mdr1 cells while mediated by lipofectamine. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression and the amount of the mdr1 mRNA in the cells. The positive rate and function of the mdr1 gene product P-glycoprotein (Pgp) in the mdr1 antisense ODNs treated SKOV3/mdr1 cells were determined by flow cytometry and rhodamine 123 efflux. Drug resistance in the SKOV3/mdr1 cell line was observed by MTT assay and cell colony culture. RESULTS: The mdr1 mRNA level was decreased to about 60% of that of beta-actin after mdr1 antisense ODNs treatment. The Pgp positive rate of mdr1 antisense ODNs treated SKOV3/mdr1 cells decreased from 100% to 52.6% (P < 0.01). The intracellular rhodamine 123 retention was increased from 9.1% to 33.8% (P < 0.01). The chemoresistance to taxol decreased to 58% of SKOV3/mdr1 with mdr1 antisense ODN treatment. Compared with SKOV3/mdr1 cells in the control group, under a certain range of drug concentrations, the number of drug resistance colonies in mdr1 antisense ODNs treated SKOV3/mdr1 cells for taxol and doxorubicin decreased by 8.6 +/- 0.8 fold and 3.1 +/- 0.6 fold, respectively. Some non-specific functions during oligodeoxyncleotide treatment was also detected. CONCLUSION: mdr1 expression in the SKOV1/mdr1 cell line was partially inhibited after mdr1 antisense ODNs treatment at the mRNA and protein level, increasing the chemotherapy sensitivity of this drug resistant ovarian carcinoma cell line.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Activity identification of anti-caspase-3 mRNA hammerhead ribozyme in both cell-free condition and BRL-3A cells.

OBJECTIVE: To study the transcription effects and cleavage activities of rat caspase-3 specific hammerhead ribozyme (Rz107) in both cell-free conditions and BRL-3A cells. METHODS: Rat caspase-3 gene fragment was cloned into the pGEM-T EASY vector under the T7 promoter control. The 32P-labeled caspase-3 transcript was the target-RNA. Rz107 genes designed against caspase-3 mRNA were cloned into vector p1.5 between 5'-cis-Rz and 3'-cis-Rz. 32P-labeled ribozyme transcripts were incubated with target-RNAs at different conditions and autoradiographed after denaturing gel-electrophoresis. Rz107 was electroporated into BRL-3A cells and the Rz107 expression was analyzed by RT-PCR. RESULTS: In cell-free conditions, Rz107 was active at 37 degrees C. The optimal temperature was 50 degrees C. The Km and Kcat were 14.13 nmol/L and 2.31.min-1 respectively. Intracellular cleavage efficiency of Rz107 was 37%, as analyzed by RT-PCR. This indicated that the design of Rz107 was correct, and Rz107 had the activity of common enzymes. CONCLUSIONS: Rz107 in cell-free conditions possessed perfect specific catalytic cleavage activity, and it can also cleave the target RNA successfully in cells. The results illustrate the feasibility of ribozyme therapy as a potential alternative approach for treating liver disease caused by apoptosis.

Animals↗

PubMed2001

[Abnormal expression of p53, Ki67 and iNOS in human esophageal carcinoma in situ and pre-malignant lesions].

OBJECTIVE: To investigate alterations in expression of Ki67, p53 and iNOS proteins in esophageal carcinogenesis. METHODS: The expression of Ki67, p53 and iNOS proteins was detected by immunohistochemical staining of 366 endoscopic biopsy specimens of the esophagus collected from high incidence area of esophageal cancer in China. If the intensity of staining was scored as > or = ++, it was regarded as overexpression. RESULTS: The overespression rate of Ki67 was 0 for normal epithelium(NE), 2.7% for mild dysplasia (MD), 11.2% for moderate dysplasia (MoD), 41.2% for severe dysplasia (SD), and 58.8% for carcinoma in-situ(CIS), respectively. That of p53 and iNOS proteins was 0 and 0 for NE, 10.1% and 4.0% for MD, 24.5% and 7.5% for MoD, 39.2% and 2.5% for SD, 48.7% and 1.4% for CIS, respectively. There was significant difference in the expression of Ki67 and p53 between normal epithelium and dysplasia of various degrees and CIS. Overexpression of Ki67 and p53 correlated well with the pathological grading of the lesions. Positive correlation was also found between p53 and Ki67 overexpressions. CONCLUSION: Overexpression of Ki67 and p53, but not iNOS, is associated with carcinogenesis of the esophagus. They are early events in esophageal carcinogenesis and useful biomarkers for early detection.

Carcinoma in Situ↗

PubMed2001

[A clinical report on hydrophilic acrylic foldable lens implantation].

OBJECTIVE: To investigate the therapeutic effects of hydrophilic acrylic foldable lens implantation. METHODS: This prospective randomized placebo-controlled study comprised 214 eyes of 190 patients after phacoemulsification. The hydrophilic acrylic foldable lens was implanted in group 1 (114 eyes), and the PMMA intraocular lens (IOL) implanted in the control group 2 (100 eyes). Within the 3-6 month follow-up period, the changes of visual acuity, corneal astigmatism and endothelial cells, the location of IOL and the degree of posterior capsular opaqueness postoperatively between the two groups were compared. RESULTS: The visual acuity of group 1 was significantly better than that of group 2 within 3 days postoperatively (P < 0.05), but there was no statistically significant difference after 3 months. The surgically induced astigmatism, incidents of posterior capsular opaqueness and subluxation of IOL of group 1 were significantly lower than that of group 2 after 3 months postoperatively (P < 0.05). The comparison of the endothelial cell loss ratio between the two groups was not significantly different (P > 0.05). CONCLUSION: The hydrophilic acrylic foldable IOL is easy to handle during implantation, highly biocompatible in the eyes, with less postoperative inflammatory reactions and shorter recovery period, and may provide satisfactory therapeutic effects.

Acrylic Resins↗

PubMed2001

[Study on drug use in elderly outpatients in Beijing].

OBJECTIVE: To understand the situation of drug use, drug request, combination of drugs and daily drug dose (DDD) among elderly patients, to provide scientific evidences for safely, effectively, economically and rationally on disease prevention and improving the quality of life of the elderly patients. METHODS: A 2-year(1998-1999) prescriptions database which was set up according to different departments of consultation, patient age, sex, consultation date, and name of drugs, dosage was used for the study. Prescriptions were randomly selected on 3-4 days in every month, from 22 hospitals in Beijing. FOXPRO software was used for statistics and analyses. Information of elderly patients (> or = 60 year) on status of drug use, was collected and compared with general patients. RESULTS: The proportion of elderly patients' prescription was 19.9%, with an average number of drugs prescribed in elderly patients 2.71, which was 0.27 higher than that of the general patients. Proportion of injections per every hundred elderly patients prescriptions was 18.4%. The major kinds of drugs were those related to cardiovasculars and vitamins. The most frequent drug was vitamin E nicotinate. DDD on elderly patients was lower than that defined by WHO and drug instruction, but higher than that of the general patients during the same period and was increasing. Daily dose of anti-hypertensions was also higher. The rate of consultation for cardiovascular diseases was high. The ratio of drugs in accordance with national essential drug list was 87.5%. CONCLUSIONS: The rates of elderly patients' prescription, average number of drugs per prescription, proportion of injections and DDD were high. The rational drug use on elderly patients should be given more concerns.

Aged↗

PubMed2001

Characterization of soluble CD40 ligand released from human activated platelets.

We report here that soluble CD40 ligand (sCD40L) is released from human platelets when activated with collagen or thrombin. The sCD40L was detectable in the culture supernatants of platelets within 30 min after stimulation in vitro, and reached maximal levels in 3 h. The release was blocked by the metalloproteinase inhibitor, KB8301, indicating that the soluble CD40L is made by cleaving the membrane bound CD40L expressed on activated platelets. The sCD40L was undetectable in the supernatant of the activated platelets obtained from patients with X-linked hyper IgM syndrome (XHIM), who have defects in CD40L gene. Since sCD40L has been shown to have biologic function on the activation of vascular endothelial cells and B cells, these findings suggest that platelets play some roles in both inflammation and humoral immune response by releasing soluble CD40L.

Antibody Formation↗

PubMed2001

[Establishment and identification of squamous cell lines carcinoma of tongue transferred with anti-sense cyclin A gene].

OBJECTIVE: The aim of this study is to investigate the relationship between cyclin A and cycle regulation of squamous cells carcinoma of tongue, and to provide basis for cancer gene therapy. METHODS: Eukaryocyte expression vector (pAS-A) containing anti-sense and the full-length human cyclin A complementary DNA (cDNA) (1.77 kb) was constructed and was transferred into squamous carcinoma of the tongue cell line (Tca8113) by Lipofect AMINETM introduction. The positive cell clones were selected with G418. Transcription of Neo gene mRNA and cyclin A mRNA were determined by in situ hybridization. The stable expression of anti-sense cyclin A in the Tca8113 cell line was determined using immunohistochemical methods. RESULTS: After G418 selection, cells transferred anti-sense cyclin A were obtained successfully. The positive cells of in situ hybridization of specific-stained Neoprobe were observed in cells transferred eukaryocyte expression vector. The positive cells of in situ hybridization of cyclin A in cells transferred anti-sense cyclin A were significantly fewer than those in cells transferred cyclin A. The positive rate of cyclin A immunohistochemical stain in cells transferred anti-sense cyclin A was significantly lower than that in cells transferred cyclin A. CONCLUSION: Human anti-sense cyclin A gene is stably expressed in the Tca8113 cell lines.

Carcinoma, Squamous Cell↗

PubMed2001

[Electrophoretic migration behavior of deoxyribonucleic acid fragments in three polymer solution concentration regions].

The theory of polymer coils shrinking in semi-dilute solution has recently been developed on polymer solution. The polymer solution from coils shrinking concentration Cs to uniform entangled concentt concentration C+ has been defined as semi-dilute solution. We experimentally investigated the electrophoretic migration behavior of 100 bp deoxyribonucleic acid (DNA) Ladder in hydroxypropyl methyl cellulose (HPMC) concentration ranging from 1.25 g/L to 16.06 g/L. The friction force mobility mu f is used to express the friction force that DNA will encounter in capillary electrophoresis. Our results indicate the division of polymer solution into three regions depending on the relationship of mu f and HPMC concentration and Ferguson plot. Resolutions of 200 bp/300 bp and 700 bp/800 bp show semi-dilute polymer solution suits large fragments and small fragments DNA separation respectively. the results confirm that the current polymer theory is valid under actual CE condition.

Attention↗

PubMed2001

[The effect of autocrine factors on development of early embryos of mouse].

Two-cell-stage embryos were flushed from the oviducts on Day 2. Zygotes were collected from oviducts on Day 1 (Fertilization In Situ, ISF) or derived from fertilization in vitro (IVF). 2-cell embryos had a high rate of blastocyst development to each embryo concentration from 1 embryo/microliter to 1 embryo/1000 microliters. The zygotes produced by either ISF or IVF were adversely affected by reducing the embryo concentration over this range (P < 0.001), with approximately 82.5% of ISF zygotes developing to blastocysts at highest concentration but only 22.3% at the lowest. For IVF zygotes the corresponding results were 46.3% and 5.2%. The number of cells in each blastocyst from 2-cell embryos was significantly higher than that from ISF and IVF group. The media supplementing Platelet-activating factor (PAF) caused a significant increase in the rate of blastocyst development of IVF zygotes at embryo concentration of 1 embryo/10 microliters (10 ng/ml) and 1 embryo/100 microliters (100 ng/ml). Insulin-like growth factor (IGF) (10 ng/ml) also stimulated development of IVF zygotes when they were cultured at the concentration of 1 embryo/10 microliters. Epidermal growth factor (EGF) was no effect over range of 1-1000 ng/ml to embryo development. The results show that factors necessary for normal embryo development are diluted to suboptimal levels during culture at low embryo concentration. The PAF, IGF-I partially compensate the effects of low embryo concentration during culture and play important roles as autocrine embryotrophic factors.

Animals↗

PubMed2001

[Effects of air pollution from burning coal on respiratory diseases in adults].

A cross sectional epidemiological study on the effect of air pollution from burning coal on the occurrence of respiratory symptoms and diseases in adults was carried out in Taiyuan city of Shanxi province. Adult residents above 25 year-old living in three areas with different degrees of pollution were selected. The results showed that the prevalence of respiratory symptoms and diseases increased with the extent of air pollution after age, sex, occupation, smoking, indoor coal-burning and history of diseases were adjusted with Logistic model.

Adult↗

PubMed2001

[Transdermal microparticle delivery by a supersonic-Helios gun system].

AIM: To investigate the effect of particle size and high speed flow of helium gas on the systemic absorption of indomethacin using a needle-less injection system. METHODS: Poly-L-lactic acid microspheres containing indomethacin was prepared by the o/w solvent evaporation technique. After anesthetizing the male hairless rat, microspheres filled in the tube cartridge was accelerated by a stream of helium gas at various velocity in the Helios gun system, and then was introduced to the abdominal skin. RESULTS: Introduction of indomethacin to the hairless rat skin was proportionally increased with enhancing the helium pressure (supersonic flow). Bioavailability and Cmax were also dependent on the helium pressure. CONCLUSION: This method can be used to deliver the powered drug and/or microparticulate systems into the skin tissues and the systemic circulation.

Administration, Cutaneous↗

PubMed2001

[Effects of leflunomide on immunological liver injury].

AIM: To study the effect of leflunomide (Lef) on immunological liver injury in mice. METHODS: Immunological liver injury was induced by tail vein injection of BCG + LPS (BCG 2.5 mg, 1 d, LPS 10 micrograms, 10 d). The ALT, AST, NO level in plasma and MDA, GSHpx in liver homogenate were assayed by spectroscopy. The serum content of TNF-alpha was determined by ELISA. IL-1, IL-2 and ConA-induced splenocyte proliferation response were determined by methods of 3H-infiltrated cell proliferation. RESULTS: Immunological liver injury induced by BCG + LPS was successfully duplicated. Lef (4, 12, 36 mg.kg-1) was found to significantly decrease the serum transaminase (ALT, AST) activity and MDA content in liver homogenate, and improved reduced GSHpx level of liver homogenate. Furthermore, Lef (4, 12, 36 mg.kg-1) significantly reduced TNF-alpha and NO level in serum, and IL-1 production by PM psi. Moreover, the decreased IL-2 production and ConA-induced splenocyte proliferation response were further inhibited. CONCLUSION: Lef showed significant protective action on immunological liver injury in mice.

Adjuvants, Immunologic↗

PubMed2001

[Pharmaceutical evaluation of fast-disintegrant tablet containing nicorandil-loaded particles].

AIM: To improve the bioavailability and taste of fast-disintegrating tablet (FD tablet) containing nicorandil-loaded particles. METHODS: A FD tablet containing nicorandil-loaded particles with 1%-4% croscarmellose sodium in addition of D-mannitol and lactose (9:1) was prepared and the dissolution and absorption characteristics were examined, in comparison with FD tablet and commercial tablets of nicorandil. In vivo absorption of nicorandil from FD tablet was evaluated in beagle dogs. RESULTS: The disintegration time of FD tablets containing 1% croscarmellose sodium with 6 mm and 10 mm in diameter were about 12 and 23 seconds, respectively. When nicorandil-loaded particles consist of myristyl alcohol and stearyl alcohol were put in FD tablet, nicorandil release from FD tablet continued until 6 h while nicorandil release from Sigmart and FD tablet containing nicorandil crystals finished within 5 min. In vivo absorption of nicorandil from Sigmart and FD tablet containing nicorandil crystals was very similar after oral administration in beagle dogs and no statistic difference in AUC, Tmax, Cmax was observed between these tablets. However pharmacokinetics parameters of nicorandil after oral administration of FD tablet containing nicorandil-loaded particles showed that nicorandil was delivered into the body at a suitable absorption rate with similar AUC, delayed Tmax and lower Cmax. CONCLUSION: The reports suggest that the modification of properties of myristyl alcohol and stearyl alcohol released from the drug-loaded particles system would lead to more acceptable bioavailability of the system. However, The formulation of particles and may have a masking effect against the bitter taste and irritation of the drug.

Administration, Oral↗

PubMed2001

[The effects of apoptosis during fracture healing].

OBJECTIVE: To elucidate the occurrence and significance of apoptosis during fracture healing of the mandible. METHODS: An experimental model of fracture was established to detect apoptosis in the different stages of healing by TdT-mediated dUTP nick end-labeling (TUNEL) method. RESULTS: Apoptosis was observed in the whole healing process. The apoptotic cells markedly increased in the stage of intramembranous bone formation (5d) and chondrogenesis (11d). CONCLUSION: Apoptosis is involved in fracture healing. The number of cells was controlled and the useless cells were eliminated by means of apoptosis. This process is helpful to the healing of tissues.

English Abstract↗

PubMed2000

Skeletor, a novel chromosomal protein that redistributes during mitosis provides evidence for the formation of a spindle matrix.

A spindle matrix has been proposed to help organize and stabilize the microtubule spindle during mitosis, though molecular evidence corroborating its existence has been elusive. In Drosophila, we have cloned and characterized a novel nuclear protein, skeletor, that we propose is part of a macromolecular complex forming such a spindle matrix. Skeletor antibody staining shows that skeletor is associated with the chromosomes at interphase, but redistributes into a true fusiform spindle structure at prophase, which precedes microtubule spindle formation. During metaphase, the spindle, defined by skeletor antibody labeling, and the microtubule spindles are coaligned. We find that the skeletor-defined spindle maintains its fusiform spindle structure from end to end across the metaphase plate during anaphase when the chromosomes segregate. Consequently, the properties of the skeletor-defined spindle make it an ideal substrate for providing structural support stabilizing microtubules and counterbalancing force production. Furthermore, skeletor metaphase spindles persist in the absence of microtubule spindles, strongly implying that the existence of the skeletor-defined spindle does not require polymerized microtubules. Thus, the identification and characterization of skeletor represents the first direct molecular evidence for the existence of a complete spindle matrix that forms within the nucleus before microtubule spindle formation.

Active Transport, Cell Nucleus↗