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Body Surface Potential Mapping↗
Biomedical subjects
J Lian
Publications and source records attributed to J Lian.
Extracellular signal-regulated kinase (ERK) activation is required for GP Ibalpha-dependent endothelial cell migration.
The GP Ib complex can participate in endothelial cell (EC) migration on von Willebrand factor (vWF) or the mixed matrix of vWF and type I collagen (vWF/collagen). In this study, viper venom proteins alboaggregin (albo) A or B blocked GP Ibalpha, and echistatin inhibited alphavbeta3 binding. Albo A, B and echistatin inhibited EC migration on vWF and vWF/collagen. Albo B or the anti-GP Ibalpha monoclonal antibody (mAb) 1b1 did not affect the migration of smooth muscle cells or fibroblasts, which lack GP Ib. EC also migrate on albo A- or albo B-coated dishes. PD98059, which blocks ERK activation, abolished EC migration on vWF, vWF/collagen, collagen or albo B. Soluble albo A or 1b1 dramatically inhibited ERK activation during EC migration on vWF or albo B. Echistatin inhibited ERK activation on vWF and vitronectin (VN), but not albo B. Thus, in addition to alphavbeta3, EC GP Ibalpha initiates ERK activation, and regulates ERK-induced EC migration on vWF.
Antibodies, Monoclonal↗
[Determination of isorhamnetine and quercetin in flavone hippophaes tablets by HPLC method].
OBJECTIVE: A method was established for the determination of isorhamnetine and quercetin in flavone hippophaes tablets by HPLC. METHODS: The HPLC system consisted of Diamonsil C18 column (250 mm x 4.6 mm, 5 microns), mobile phase of methanol-0.02 mol/L phosphoric acid (54:46), column temperature at 40 degrees C, with detection at 368 nm. RESULTS: The linear range of isorhamnetine and quercetin were 6.5-32 micrograms/ml (r = 0.9996) and 2.5-12.4 micrograms/ml (r = 0.9991). The average recoveries were 99.4% and 99.8%, respectively. The within-day precision RSD were 1.22% and 1.32% (n = 6), and the day-to-day precision RSD were 1.07% and 1.35% (n = 5), respectively. CONCLUSION: This method is simple and accurate. It is suitable for the preparation quality control.
Chromatography, High Pressure Liquid↗
Interaction of CBF alpha/AML/PEBP2 alpha transcription factors with nucleosomes containing promoter sequences requires flexibility in the translational positioning of the histone octamer and exposure of the CBF alpha site.
Chromatin remodeling at eukaryotic gene promoter sequences accompanies transcriptional activation. Both molecular events rely on specific protein-DNA interactions that occur within these promoter sequences. Binding of CBFalpha/AML/PEBP2alpha (core binding factor alpha/acute myelogenous leukemia/polyoma enhancer binding protein 2alpha) proteins is a key event in both tissue-specific and developmentally regulated osteocalcin (OC) promoter activity. To address linkage between chromatin organization and transcription factor binding, we reconstituted segments of the rat OC gene proximal promoter into mononucleosomes and studied binding of CBFalpha proteins. We analyzed binding of bacterially produced Cbfalpha2Alpha and Cbfalpha2B, two splice variants of the human CBFalpha2 gene, and determined the effect of heterodimerization with the Cbfbeta subunit on binding activity. Our results indicate that binding of the truncated Cbfalpha2A protein to naked DNA is independent of Cbfbeta whereas Cbfalpha2A binding to nucleosomal DNA was enhanced by Cbfbeta. In contrast, the Cbfalpha2B interaction with either naked or nucleosomal DNA was strongly dependent on heterodimerization with the Cbfbeta subunit. Additionally, our results demonstrate that both Cbfalpha2A alone and Cbfalpha2B complexed with Cbfbeta can interact with nucleosomal DNA only if there is a degree of flexibility in the positioning of the histone octamer on the DNA fragment and exposure of the CBFalpha site. This situation was achieved with a DNA segment of 182 bp from the rat OC promoter that preferentially positions mononucleosomes upstream of the CBFalpha binding site and leaves this element partially exposed. Taken together, these results suggest that nucleosomal translational positioning is a major determinant of the binding of CBFalpha factors to nucleosomal DNA.
Animals↗
Evaluation of endothelial cell migration with a novel in vitro assay system.
In this study we introduce a novel in vitro 'oil-drop' assay system for the measurement of endothelial cell (EC) migration, based on the original concept of the Teflon fence assay (Pratt et al., 1984; Am. J. Pathol. 117: 349-354). An aliquot of 15-20,000 human umbilical vein EC (HUVEC) is pipetted through a layer of mineral oil. The cells readily attach, spread and migrate on the surface of a matrix-coated tissue culture dish as a confluent circular monolayer. Migration is measured as the net increase in the total area covered at 24 hours. We have used this system to quantify EC migration on matrices composed of a mixture of type I collagen and either von Willebrand factor (vWF) or fibronectin (FN) in the presence or absence of tumor necrosis factor alpha (TNFalpha). Plating efficiency on both vWF/collagen and FN/collagen, measured by counting cells after attachment and spreading, is about 80%. With this method, migration on vWF/collagen was about 6.4 mm(2) and 5.3 mm(2) for TNFalpha-treated and untreated HUVEC, respectively. HUVEC migration on FN/collagen was slightly greater - 6.4 mm(2) and 6.5 mm(2) with and without TNFalpha treatment, respectively. During the 24 hour time period, HUVEC numbers increased 30-40% on vWF/collagen, and 60-80% on FN/collagen, with increased proliferation observed with TNF-alpha treatment. EC proliferation could be completely inhibited by 2 mM hydroxyurea. This assay system has proven useful in our studies to quantify cell migration and proliferation.
Cell Movement↗
Developmental regulation of thyrotropin receptor gene expression in the fetal and neonatal rat thyroid: relation to thyroid morphology and to thyroid-specific gene expression.
The TSH receptor plays a pivotal role in thyroid gland function, growth, and differentiation, but little is known about its role or regulation in the fetus and neonate. To explore these questions, we systematically evaluated TSH receptor gene expression at the level of messenger RNA (mRNA) in thyroid glands obtained from rat fetuses and neonates, from 14 days gestation to day 5 of postnatal life. Results were compared with histological evidence of differentiation and to thyroid-specific gene expression. Northern blot and RT-PCR analysis revealed that TSH mRNA was first detected at low levels on fetal day 15, but it increased 3- to 15-fold on fetal days 17-18. Up-regulation of TSH receptor mRNA on fetal day 17-18 was accompanied by the first appearance of colloid formation and of follicular development on morphological examination. It was also paralleled by increased expression of the thyroid-specific genes thyroglobulin (Tg) and thyroid peroxidase. Unexpectedly, TSH mRNA abundance was 2- to 3-fold higher in pregnant dams than in nonpregnant adult females or adult males. In view of the 8-day lapse between the first appearance of the thyroid diverticulum and up-regulation of TSH receptor gene expression, we conclude that pituitary TSH, acting through its receptor, plays an important role in terminal thyroid maturation, but it is not involved earlier in gestation. Similarly, these data support previous evidence that the weak thyrotropic activity of human CG could not be of significance in early fetal thyroid gland development. The increased TSH receptor mRNA on fetal day 17-18 may be attributable to up-regulation by TSH, which is first secreted into the fetal circulation at this time. The significance of the increased TSH receptor expression during pregnancy remains to be explored.
Animals↗
Self-reported musculoskeletal disorders among visiting and office home care workers.
This paper examines the associations between self-reported musculoskeletal disorders (MSDs) and work factors and injuries among home care workers. Based on 99 focus group participants and 892 survey respondents, results show a high level of MSDs among both visiting and office home care workers. While visiting home care workers tend to feel pain in the back, office workers tend to report pain in the neck and shoulder. Hazards in clients' homes, injuries moving clients and stress are associated with self-reported MSDs for visiting home care workers. Repetitive tasks and stress are associated with self-reported MSDs for office home care workers. Age and months in the profession have no affect on self-reported MSDs.
Canada↗
[Expression of nm23 protein and estrogen receptor and prognosis of colorectal cancers].
OBJECTIVE: To explore the relationship between clinicobiological action and expression of nm23 protein and estrogen receptor (ER) for colorectal cancer. METHODS: The expression of nm23 protein and ER for 209 cases of colorectal cancer was detected by immunohistochemistry assay (LSAB). RESULTS: The expression of nm23 protein was correlated with that of ER for colorectal cancer (r = 0.5319, P < 0.01). The expression of nm23 protein and ER in colorectal cancers was not related with patient's age, sex, tumor position, pathological type, histological type, and Dukes stage (r < 0.4, P > 0.05). The expression was related with the prognosis of colorectal cancer (P < 0.01). The higher the expression of nm23 protein and/or ER the better the prognosis, whereas the less the expression of nm23 protein and/or ER the worse the prognosis. CONCLUSIONS: The abnormal expression of nm23 protein is correlated with the disturbance of estrogen metabolism in colorectal cancer. The detection of nm23 protein and ER is helpful for the diagnosis and prognostic evaluation of colorectal cancer.
Adult↗
The changes of TGF-alpha, TGF-beta 1 and basic FGF messenger RNA expression in rabbit cornea after photorefractive keratectomy.
OBJECTIVE: To study the mechanism of haze formation and investigate the expression changes of transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1(TGF-beta 1) and basic fibroblast growth factor (bFGF) mRNA in corneal epithelium and stroma after photorefractive keratectomy (PRK). METHODS: Sixteen white rabbits were randomly divided into 4 groups, and PRK was performed on each eye of 12 rabbits. The haze formation was examined under a slit-lamp microscope at the 1st, 2nd and 3rd month after PRK, and the expressions of TGF-alpha, TGF-beta 1 and bFGF mRNA were detected with in situ hybridization. RESULTS: The corneal haze formed at the 1st month after PRK. The most prominent haze formation was observed at the 2nd month, and declined gradually at the 3rd month after ablation. TGF-alpha mRNA expression was presented on the normal corneal epithelium and not on the corneal stroma. TGF-beta 1 and bGFG mRNA were expressed by both corneal epithelium and stroma. The capacities for cornea tissue expression of three growth factors mRNA increased after PRK, and the peaks appeared on the 1st, 2nd month. The extent for expressions of three growth factors related proportionally to the haze formation. CONCLUSION: Three growth factors took part in promoting corneal wound healing after PRK, and might contribute to corneal haze formation and development.
Animals↗
Glycoprotein Ibalpha can mediate endothelial cell migration on von Willebrand factor-containing substrata.
We have previously shown that, in addition to the vitronectin receptor (VNR, alpha(v)beta(3)), the GP Ib complex can participate in endothelial cell (EC) attachment to von Willebrand Factor (vWF) (D. A. Beacham, M. S. Cruz, and R. I. Handin, 1995, Thromb. Haemostas. 73, 309-317; D. A. Beacham, L.-P. Tran, and S. S. Shapiro, 1997, Blood 89, 4071-4077). In this study we have investigated the functional roles of these vWF receptors in the migration of untreated and TNFalpha-treated EC on vWF, a mixture of vWF and type I collagen, and on vitronectin (VN). In agreement with previous studies (D. I. Leavesley, M. A. Schwartz, M. Rosenfeld, and D. A. Cheresh, 1993, J. Cell Biol. 121, 163-170), the migration of untreated and TNFalpha-treated EC on VN was dependent entirely on the VNR. Migration of untreated EC on vWF was inhibited 10-15% by recombinant vWF-A1, the GP Ibalpha-binding domain on vWF which abrogates the platelet GP Ibalpha-vWF interaction. In contrast, migration of TNFalpha-treated EC on vWF was inhibited 50-60% by vWF-A1 or the anti-GP Ibalpha mAb AS-7 but only 20% by the anti-VNR mAb LM609. On a mixed vWF-collagen substratum, vWF-A1 inhibited untreated EC migration by 45%, and TNFalpha-treated EC migration by 75%. The possible role of EC proliferation was eliminated, since hydroxyurea completely inhibited EC proliferation without reducing migration significantly. The anti-GP Ibalpha mAb Ib1 inhibited EC migration by 50%, but reduced proliferation by only 15%. Taken together, our data demonstrate that EC migration on vWF-containing substrata involves the GP Ib complex as well as the VNR and raises the possibility that the VNR and GP Ib act cooperatively in supporting EC migration.
Antibodies, Monoclonal↗
Arterial shear stress stimulates surface expression of the endothelial glycoprotein Ib complex.
Exposure to shear stress has been shown to alter the expression of a number of surface components of cultured endothelial cells (EC). However, relatively few studies have examined the status of human EC surface proteins after prolonged flow, more closely corresponding to the steady state in vivo. Since the promoter region of glycoprotein (Gp) Ib alpha contains several copies of a putative shear stress response element, 5'-GAGACC-3', we investigated the response of cultured human umbilical vein EC (HUVEC) GpIb alpha to shear stress over a 72 h time period. In response to 30 dynes/cm2 of shear stress, total cell content of GpIb alpha protein was markedly increased above static levels at 7 and 24 h, as determined immunohistochemically. Western blot analysis of whole cell lysates after 24, 48, and 72 h of shear treatment demonstrated a 2.4-, 4.1-, and 3.2-fold increase in total GpIb alpha protein, respectively. Cell surface protein expression of GpIb alpha increased 2.5-fold at 7 h, as measured by quantitative immunofluorescence, and remained at that level at 24 h. After 48 h of shear stress, cell surface GpIb alpha, GpIX, and GpV, analyzed by flow cytometric analysis, were further increased over the levels observed at 24 h. The increase in cell surface membrane expression of GPIb alpha at 24, 48, and 72 h was confirmed by immunoprecipitation of biotinylated surface proteins. No upregulation of GpIb alpha was noted after exposure to shear stress of 1-3 dynes/cm2. These observations imply that under steady-state arterial shear conditions endothelial expression of the GpIb complex is significantly greater than observed in static EC cultures, and raise the possibility of a more important role for this complex under flow, rather than static conditions.
Arteries↗
[Immune responses to recombinant expression plasmid encoding hepatitis C virus core antigen].
OBJECTIVE: To study the feasibility of DNA immunization with recombinant expression plasmid containing hepatitis C virus (HCV) core gene against HCV infection. METHODS: The recombinant plasmid containing HCV C gene was constructed and expressed transiently by using lipofectamine in the mouse SP2/0 cells. After appraisal and purification, these plasmid and control DNA were directly injected intramuscularly into BALB/c mice, HCV C specific antibody in the sera was checked with ELISA. Proliferative responses of spleen cells from experimental and control mice were determined by (3)H thymidine incorporation and cytotoxicity T lymphocyte (CTL) activity was measured by standard 4-h (51)Cr release assays. RESULTS: All immunized mice developed anti-HCV core antibodies and this antibody was dose and immune number dependent. Lymphoproliferative responses for HCV core antigen were higher in immunized mice than in control mice (P < 0.05), stimulation indices (SI) were 2.42 - 6.10. CTLs might induce approximately 63.13% lysis of pcDNA HCV C transfected SP2/0 target cells. CONCLUSION: It is suggested that HCV C gene immunization is a promising method of vaccination against HCV infection.
Animals↗
[The immunohistochemical changes of TGF-beta, type I and III collagen in corneal healing after photorefractive keratectomy].
OBJECTIVE: To observe the immunohistochemical expression of transforming growth factor-beta (TGF-beta), type I and III collagen in monkey corneal healing after photorefractive keratectomy (PRK) and find whether TGF-beta is involved in the process of corneal healing and correlated with the syntheses of type I and III collagen. METHODS: Three rhesus monkeys (6 eyes) were operated for myopic ablation of 10.0 diopters. The depth of ablation was 103 microm. Microscopy, transmission electron microscopy and immunohistochemistry were performed at 1, 3 and 6 months after PRK. RESULTS: TGF-beta staining was positive in the epithelium and a few fibroblasts under the epithelium at one month after the operation. The staining was negative at 6 months and in the control specimens. Postoperatively, type I and III collagen stainings were evident at 1, 3 and 6 months. Type I collagen staining was positive and type III was negative in the controls. CONCLUSION: TGF-beta is involved in the corneal healing after PRK, and perhaps correlated with the syntheses of type I and III collagen.
Animals↗
[Analysis of intraocular pressure and corneal thickness after laser in situ keratomileusis].
OBJECTIVE: To analyze the changes and relationship of the intraocular pressure (IOP) and the corneal thickness (CT) after laser in situ keratomileusis (LASIK). METHODS: This prospective study comprised two groups: noncontact tonometer group 221 eyes (156 patients) 1 month after LASIK and 72 eyes (50 patients) 3 months after LASIK; Goldmann applanation tonometer group 60 eyes (36 patients) 1 month after LASIK. The spherical equivalent, the corneal thickness and the IOP readings were measured pre- and post-LASIK. RESULTS: The CT was thicker than the predicted value and it was much more prominent in the higher myopic group with more regression degree of refraction. The CT at postoperative 3 month was thicker than that at 1 month. There was a statistical decrease in mean tonometer readings, both with non-contact tonometer and Goldmann applanation tonometer; and there was statistically significant correlation between the changes of central corneal thickness and the changes of non-contact tonometer readings (r = 0.2, P < 0.002). The IOP decrease with Goldmann applanation tonometer was less than that with noncontact tonometer. CONCLUSIONS: The actual ablation depth of cornea is lower than the predicted. The IOP readings of the patients after LASIK are lower than the real IOP values. Further efforts should be made to improve the accuracy. Goldmann applanation tonometer is a better choice measuring IOP after excimer photoablative corneal refractive surgery.
Adolescent↗
Nuclear matrix associated DNA-binding proteins of ocular lens epithelial cells.
Association of transcription factors with the nuclear matrix represents a mechanism by which nuclear architecture may influence transcriptional control of gene expression. This investigation examines nuclear matrix associated proteins (NMP's) isolated from ocular lens epithelial cells by monitoring DNA binding activities using consensus oligonucleotides recognized by the transcription factors YY1, AML-1, AP-1, SP-1 and ATF. The nuclear matrix fractions tested included an immortilized human lens epithelial cell line containing the SV40 large T-antigen, and two mouse lens epithelial cell lines derived from either a normal mouse or a cataract mouse. A rabbit epidermal epithelial cell line and HeLa cells were also included in this study for comparison. The data from these experiments reveal that ubiquitously represented and tissue restricted regulatory proteins are associated with nuclear matrix of lens epithelial cells. The functional significance of the nuclear matrix association of these transcription factors remains to be determined. However, our findings raise the possibility that the transcription factors associated with the nuclear matrix could have specific roles in gene regulation and eye tissue development.
Animals↗
A novel frameshift mutation induced by an adenosine insertion in the polycystic kidney disease 2 (PKD2) gene.
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common Mendelian disorders and is genetically heterogeneous. Linkage studies have shown that the majority (approximately 85%) of ADPKD cases are due to mutations in PKD1 on chromosome 16p13.3, while mutations in PKD2 on chromosome 4q21-q23 are thought to account for most of the remaining cases. In this report, we describe the mutation in a large four-generation ADPKD family (TOR-PKD77) which we had mapped to the PKD2 locus by linkage analysis. In this family, we screened for mutations by directly sequencing two nested RT-PCR fragments (PKD2N1 and PKD2N2) that cover approximately 90% of the PKD2 open reading frame. In the affected members, we identified a novel single adenosine insertion (2160InsA) in the PKD2N2 fragment. This mutation occurred in the polyadenosine tract (nt2152-2159) of exon 11 and is predicted to result in a frameshift with premature translation termination of the PKD2 product, polycystin 22, immediately after codon 723. The truncated polycystin 2 is predicted to lack the calcium-binding EF-hand domain and two cytoplasmic domains required for the homodimerization of polycystin 2 with itself and for the heterodimerization of polycystin 2 with polycystin 1.
Adenosine↗
[Corneal topography analysis after excimer laser photorefractive keratectomy].
OBJECTIVE: To study the pattern of ablation, evaluate centration and stability following excimer laser photorefractive keratectomy (PRK) for myopia. METHOD: Corneal topography of 312 patients (366 eyes) with a month, 3 months and 6 months of follow-up after PRK was examined. RESULTS: The mean decentration from the pupillary center to ablating center was 0.266 mm. In both eyes, the mean decentration was located supernasally. At one month postoperative examination, uniform ablation was 49.5%, semicircular, keyhole, kidney and dumbbell shaped ablations were 42.9% and central island one was 6.0%. Central island pattern affected the best corrected visual acuity greatly. High myopia began regression at 1-3 months after PRK. CONCLUSION: Corneal topography is essential for evaluating surface changes after PRK. Long-time stability issues are answered with continued topographic follow-up.
Corneal Topography↗
[Excimer laser in situ keratomileusis for treatment of myopia].
OBJECTIVE: To evaluate the effectiveness of excimer laser in situ keratomileusis (LASIK) for treatment of myopia. METHODS: 928 eyes of 678 myopic patients who received LASIK were studied. The patients were divided into 3 groups according to preoperative diopters (-2.00 - -6.00D, -6.10 - -10.00D & -10.10 - -20.00D). The mean follow-up was 12 months (6 - 18 months) and the results were statistically analyzed. RESULTS: 12 months after surgery, in the first group the mean residual refraction was -0.24 +/- 0.50D in 86% and 92% of eyes were in the ranges of refraction +/- 0.50D and +/- 1.00D, the uncorrected visual acuities of 0.5 and 1.0 were in 99% and 86% of the eyes respectively. In the second group, the mean residual refraction was -0.47 +/- 0.64D, the refraction of 83% and 90% of eyes was in the ranges of +/- 0.50D and +/- 1.00D, and the uncorrected visual acuities in 95% and 79% of eyes were 0.5 and 1.0 respectively. In the third group, the mean residual refraction was -0.89 +/- 1.02D, the refraction of 36% and 62% of the eyes were in the ranges of +/- 0.50D and +/- 1.00D, and the uncorrected visual acuities in 68% and 45% of the eyes were 0.5 and 1.0 respectively. 47 eyes had been retreated with LASIK. 5 eyes lost two or more lines of the best corrected visual acuity due to irregular astigmatism, decentration and progressive myopic maculopathy. CONCLUSION: The results indicate that LASIK can treat myopia in the range of -2.00 - -20.00 D effectively without vision threatening complications. Some modification of the surgical techniques and laser nomogram will help to improve predictability and stability of outcome.
Adolescent↗