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Chun Zhang

Publications and source records attributed to Chun Zhang.

At least 55 records · Page 3Linked to original sources
PubMed2005

STAT3 activation in response to growth factors or cytokines participates in retina precursor proliferation.

Growth factors and cytokines play an important role in the development of central nervous systems including neurons of the retina. However, the molecular pathways that trigger cell growth remain unclear in neuronal precursors. In the present studies, we used a retinal explant culture system to investigate the response of signal transducer and activator of transcription factors (STATs) to extrinsic factors during mouse retinal development. Retinas from embryonic and neonatal stages showed that STAT3 but not STAT1 was activated in response to ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), fibroblast growth factor-1 (FGF1), fibroblast growth factor-2 (FGF2), epidermal growth factor (EGF), interferon-alpha (IFN-alpha) and interferon-gamma (IFN-gamma) in distinct patterns. STAT3 activation was detected in the outermost retina layer in response to CNTF, LIF, FGF1, and IFN-alpha 24 hr after stimulation in postnatal day 1 (PN1) explants, but not FGF2, EGF, IFN-gamma, and retinoic acid (RA). Cytokine stimulation increased the number of cells incorporating BrdU and the labelled cells co-localized with phosphorylated STAT3, indicating that STAT3 may play an essential role in coupling extrinsic factors to retina precursor cell (RPC) proliferation. Furthermore, persistent expression of two neural precursor markers, Hes1 and Otx2 was detected in outer retinal layers and correlated with STAT3 activation by CNTF, suggesting that STAT3 activation may play a critical role in stimulating mitotic precursors. These results strongly support a model that STAT3-mediated signalling regulates precursor populations during mouse retina development.

Animals↗
PubMed2005

Design and expression of peptide antibiotic hPAB-beta as tandem multimers in Escherichia coli.

Peptide antibiotics are small peptides encoded by organism genomic DNA. They are recognized to play important roles in the innate host defense of most living organisms. The growing resistance of bacteria to conventional antibiotics and the need for discovery of new antibiotics have stimulated great interest in the development of peptide antibiotics as human therapeutics. However, preparation of peptide antibiotics at a large scale is a great challenge in developing these commercial products. In this study, tandem repeat multimers of peptide antibiotic hPAB-beta were designed and the recombinant plasmids containing one to eight copies of hPAB-beta gene were generated. Eight genetic engineered bacteria harboring pQE-hPAB-beta1-8 recombinant were able to express the repetitive hPAB-beta multimers of interest in inclusion bodies, respectively. The expressed proteins could reach 2.6-28% of the total proteins. The hPAB-beta trimer construct was selected out for the subsequent study based on its higher expression level (27.8%), which yields in wet cell weights (3.15+/-0.45 g/l) and the fusion protein inclusion bodies was able to completely dissolve in 8 M urea. The tandem trimers could easily be captured by Ni-NTA affinity chromatography and cleaved into monomers by hydroxylamine. Then, the monomer hPAB-beta of interest was purified to 95% homogeneity by reverse phase chromatography and gel filtration. The final yield of purified recombinant monomer hPAB-beta was 680+/-12 mg/100 g wet cells. The minimum inhibitory concentrations (MICs) of the purified recombinant hPAB-beta against type or clinical strains of microorganisms were about 31-250 microg/ml and these results showed that the recombinant hPAB-beta could retain its bioactivity.

Amino Acid Sequence↗
PubMed2005

DNA vaccination with naked DNA encoding MCP-1 and RANTES protects against renal injury in adriamycin nephropathy.

BACKGROUND: We have previously shown that monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T-cell expressed and secreted (RANTES) are significantly increased in renal cortex in adriamycin nephropathy. In this study, we tested the effect of DNA vaccination encoding the C-C chemokines MCP-1 and RANTES in a rat model of adriamycin nephropathy. METHODS: Both reverse transcription-polymerase chain reaction (RT-PCR) products of MCP-1 and RANTES used as constructs were cloned into a pTarget vector for naked DNA vaccination. Two hundred micrograms of DNA was injected into the tibialis anterior muscle four times at weekly intervals. One week after the last DNA vaccination, rats received adriamycin. All animals were sacrificed 4 weeks after adriamycin administration. Changes in renal function and histologic features were assessed. Enzyme-linked immunosorbent assay (ELISA) and Western blot were used for autoantibody determination. Antibody specificity was assessed in in vitro transmigration assays. RESULTS: Chemokine DNA vaccination significantly reduced proteinuria (P < 0.05) and ameliorated creatinine clearance (P < 0.05) at 2, 3, and 4 weeks after adriamycin administration. Morphometric analysis showed less glomerular sclerosis (P < 0.001) and interstitial infiltrates (P < 0.005) in chemokine DNA vaccination group compared with control groups. Anti-MCP-1 and RANTES autoantibodies were detected in higher concentrations in chemokine DNA vaccinated rats than in control rats (P < 0.001) and serum from vaccinated rats blocked T-cell transmigration to MCP-1 and RANTES. CONCLUSION: In this study, we have shown that naked DNA vaccination against MCP-1 and RANTES ameliorates the progression of renal disease in the rat adriamycin nephropathy model of chronic proteinuric renal disease. The protective mechanism may involve the production of autoantibodies against MCP-1 and RANTES.

Animals↗
PubMed2005

Can murine diabetic nephropathy be separated from superimposed acute renal failure?

BACKGROUND: Streptozotocin (STZ) is commonly used to induce diabetes in experimental animal models, but not without accompanying cytotoxic effects. This study was undertaken to (1) determine an optimal dose and administration route of STZ to induce diabetic nephropathy in wild-type mice but without the concurrent acute renal injury resulting from cytotoxic effects of STZ and (2) evaluate the pattern of tubular injury and interstitial inflammation in this model. METHODS: Male Balb/c mice received either (1) STZ (225 mg/kg by intraperitoneal injection.); or (2) two doses of STZ 5 days apart (150 mg/150 mg/kg; 75 mg/150 mg/kg; 75 mg/75 mg/kg; and 100 mg/100 mg/kg by intravenous injection). Another strain of mice, C57BL/6J, also received STZ (200 mg/kg intravenously or intraperitoneally). Renal function and histology were examined at weeks 1, 2, 4, and 8 after induction of diabetes. In initial optimization studies, animals were sacrificed at week 1 or week 2 and histology examined for acute renal injury. RESULTS: Following a single intraperitoneal injection of 225 mg/kg of STZ, only two thirds of animals developed hyperglycemia, yet the model was associated with focal areas of acute tubular necrosis (ATN) at week 2. ATN was also observed in C57BL/6J mice given a single intravenous or intraperitoneal dose of STZ (200 mg/kg), at week 2 post-diabetes. At an optimal diabetogenic dose and route (75 mg/150 mg/kg by intravenous injection 5 days apart), all mice developed diabetes and no ATN was observed histologically. However, even with this regimen, glomerular filtration rate (GFR) was significantly impaired from week 2. This regimen was accompanied by progressive histologic changes, including tubular and glomerular hypertrophy, mesangial area expansion, as well as interstitial macrophage, CD4+ and CD8+ T-cell accumulation. CONCLUSION: By careful optimization of STZ dose, a stable and reproducible diabetic murine model was established. However, even in this optimized model, renal functional impairment was observed. The frequency of ATN and functional impairment casts doubt on conclusions about experimental diabetic nephropathy drawn from reports in which ATN has not been excluded rigorously.

Acute Kidney Injury↗
PubMed2005

[Evidence of the unreduced diploid eggs generated from the diploid gynogenetic progeny of allotetraploid hybrids].

Following activation by UV-irradiated sperms from scatter scale common carp and without the treatment for doubling the chromosome number, the eggs generated by the diploid gynogenetic progeny (G1) with 100 chromosomes,developed into diploid gynogenetic progeny (G2) with 100 chromosomes. Both the males and females of the tetraploids with 200 chromosomes were obtained from the offsprings (G1 x AT) produced by mating the eggs of G1 with the diploid sperms from the allotetraploid hybrids. The results provided the evidence that diploid G1 is able to produce diploid eggs. In the oogonia of diploid six-month old G2, only the chromosomes in the metaphase of mitosis were observed in all slides, no bivalent chromosome being found, suggesting that the oogonia in six-month old G2 were not mature enough for meiosis I. The presence of the chromosome spreads with 100, 200 and 380 chromosomes observed in the metaphase indicated that the diploid G2 had the potential ability to generate diploid eggs with the probable mechanism of pre-meiotic endoreduplication. In contrast, the spermatocytes of G1 x AT allotetraploids had the normal chromosomal behavior with only 100 bivalents found in meiosis I. The one-year old G2 possessed the slowly developmental ovaries which stayed at the oogonium stage for a long time, in which no primary and mature oocyte was found, whereas both the females and males of one-year old G1 x AT allotetraploids had normal ovaries and testes which reached maturity and produced diploid eggs and diploid sperms, respectively. The formation of the diploid eggs generated from the diploid gynogenetic progeny makes it available to establish a diploid hybrid clonal line, and will become an important source of production of diploid eggs. In addition, the bisexual fertile G1 x AT allotetraploids enriched the types of the tetraploids.

Animals↗
PubMed2005

[Clinical research on 2228 cases of thyroid gland tumors].

OBJECTIVE: To discuss outcome of thyroid tumor patients treated with surgery. METHODS: Total number of patients was 2228. These patients of thyroid tumors from 1992-2004 (2072 cases of benign thyroid diseases and 156 cases of thyroid carcinoma) were recruited. The clinical and follow-up datum were retrospective analyzed. RESULTS: (1) Benign thyroid tumors with near-total thyroidectomy including 1761 thyroid adenoma, 207 nodular goiter and 104 Hashimoto thyroiditis, the incidence of recurrent laryngeal nerve paralysis was 0.2%, 55 cases (2.6%) received secondary surgery. All the patients have no hypocalcemia or hemorrhage after operation. (2) Eighty-one cases of papillary carcinoma of the thyroid ( > 1 cm) and 60 cases of microcarcinoma. Unilateral thyroidectomy, contralateral near-total thyroidectomy and ipsilateral modified neck dissection were performed in unilateral papillary carcinoma of thyroid. Among the 9 cases of follicular carcinoma of thyroid, 7 were performed of near-total thyroidectomy without neck dissection, others were the same as papillary carcinoma. Bilateral total thyroidectomy and bilateral modified neck dissection were performed in 2 cases of the medullary thyroid cancer and 1 case of the undifferentiated thyroid cancer. By direct method the 5-year survival was 95.5% (64/67), and by Kaplan-Meier method, it was 98.0%. The treatment of microcarcinoma are multiple. There is no relapse or metastases in 60 cases of papillary thyroid microcarcinoma. The 5-year survival was 100.0%, 1 cases occurred recurrent laryngeal nerve paralysis in thyroid cancer. No hypocalcemia or hemorrhage. Eight case relapsed in 156 cases of thyroid carcinoma,3 cases died. CONCLUSION: The correct surgical management for the patients with thyroid tumor should benefit for the prognosis and reduce the complications and the recurrence of the operation.

Adolescent↗
PubMed2005

[Studies on vision mediated behavioral changes of rat with photic injury].

OBJECTIVE: To evaluate the relationship of visual function and photoreceptor cell loss, and to establish a visual function assessment system based on the observation of optokinetic behavior in rat with photic injury. METHODS: SD rats were exposed to (950 +/- 50) lux green light for 3 hours, 12 hours and 24 hours respectively after 24-hour dark adaptation. Then 24-hour dark recovery was followed by 48-hour observation before the eyes were enucleated. Frozen sections were obtained. Slides were stained by HE and rhodopsin immunofluorescent stainings. Vision mediated disturbance of consciousness and pre-pulse response were used to assess the visual function. Optokinetic behavior test was conducted 2 days before and after photic injury. Average velocity of motion were analyzed. RESULTS: Vision mediated disturbance of consciousness response are gradually weakened; while pre-pulse response is reinforced as the photic injury time increases. The relationship of optokinetic behavior and rat visual function is statistically significant. Optokinetic behavior test shows the average velocity of motion gradually decreases as the injury is aggravated. CONCLUSIONS: Longer light exposure time leads to increased photoreceptor injury, which in turn, causes decrease of visual function in SD rat. Optokinetic behavior test, represented by average velocity of motion, is correlated with rat visual function. Thus, optokinetic behavior test can be used to assess the visual function of SD rat quantitatively.

Animals↗
PubMed2004

Loss of parafibromin immunoreactivity is a distinguishing feature of parathyroid carcinoma.

PURPOSE: A reliable method for diagnosing parathyroid carcinoma has remained elusive over the years, resulting in its under-recognition and suboptimal therapy. Obtaining an accurate diagnosis has become an even more pressing matter with recent evidence that germline HRPT2 gene mutations are found in patients with apparently sporadic parathyroid carcinoma. There is a high prevalence of HRPT2 gene mutations and biallelic inactivation in parathyroid carcinoma. We hypothesize that loss of parafibromin, the protein product of the HRPT2 gene, would distinguish carcinoma from benign tissue. EXPERIMENTAL DESIGN: We generated a novel antiparafibromin monoclonal antibody and performed immunostaining on 52 definite carcinoma specimens, 6 equivocal carcinoma specimens, 88 benign specimens, and 9 hyperparathyroidism-jaw tumor (HPT-JT) syndrome-related adenomas from patients with primary hyperparathyroidism from nine worldwide centers and one national database. RESULTS: We report that the loss of parafibromin nuclear immunoreactivity has 96% sensitivity [95% confidence interval (CI), 85-99%] and 99% specificity (95% CI, 92-100%) in diagnosing definite carcinoma. Inter-observer agreement for evaluation of parafibromin loss was excellent, with unweighted kappa of 0.89 (95% CI, 0.79-0.98). Two equivocal carcinomas misclassified as adenomas were highlighted by parafibromin immunostaining. One of these tumors has since recurred, satisfying criteria for a definite carcinoma. Similarly, eight of nine HPT-JT syndrome-related adenomas showed absent nuclear immunoreactivity. CONCLUSIONS: Parafibromin is a promising molecular marker for diagnosing parathyroid carcinoma. The similar loss of parafibromin immunoreactivity in HPT-JT syndrome-related adenomas suggests that this is a pivotal step in parathyroid tumorigenesis.

Antibodies, Monoclonal↗
PubMed2004

Role of connective tissue growth factor in renal tubular epithelial-myofibroblast transdifferentiation and extracellular matrix accumulation in vitro.

Connective tissue growth factor (CTGF) has been reported to play an important role in mediating the profibrotic effects of transforming growth factor-beta (TGF-beta) in the pathogenesis of renal fibrosis. To further elucidate the role of CTGF in renal tubular transdifferentiation and extracellular matrix (ECM) metabolism, we examined the time-course of CTGF, alpha-smooth muscle actin (alpha-SMA), fibronectin and plasminogen activator inhibitor-1(PAI-1) gene expression upon the stimulation of TGF-beta1 (5 microg/L) in cultured human proximal tubular epithelial cell line (HKC), and further investigated the effects of endogenous CTGF blockade. On reverse transcriptional-polymerase chain reaction (RT-PCR) analysis, TGF-beta1 upregulated CTGF gene expression, preceding that of alpha-SMA, fibronectin and PAI-1. The alpha-SMA, fibronectin and PAI-1 mRNA expression induced by TGF-beta1 were significantly inhibited by CTGF antisense oligodeoxynucleotide (ODN) transfection. With prolonged incubation time, CTGF antisense ODN also inhibited intracellular alpha-SMA and PAI-1 protein synthesis, lowered the level of fibronectin and PAI-1 protein secreted into the media, as confirmed by indirect immuno-fluorescence, flow cytometry, enzyme-linked immunosorbent assay (ELISA) and Western blot methods respectively. These results suggested that CTGF may play a crucial role in the renal tubular epithelial-transdifferentiation and the following deposition/degradation process of ECM during tubulointerstitial fibrosis.

Actins↗
PubMed2004

A hidden Markov modeling approach for admixture mapping based on case-control data.

Admixture mapping is potentially a powerful method for mapping genes for complex human diseases, when the disease frequency due to a particular disease-susceptible gene is different between founding populations of different ethnicity. The method tests for association of the allele ancestry with the disease. Since the markers used to define ancestral populations are not fully informative for the ancestry status, direct test of such association is not possible. In this report, we develop a unified hidden Markov model (HMM) framework for estimating the unobserved ancestry haplotypes across a chromosomal region based on marker haplotype or genotype data. The HMM efficiently utilizes all the marker data to infer the latent ancestry states at the putative disease locus. In this HMM modelling framework, we develop a likelihood test for association of allele ancestry and the disease risk based on case-control data. Existence of such association may imply linkage between the candidate locus and the disease locus. We evaluate by simulations how several factors affect the power of admixture mapping, including sample size, ethnicity relative risk, marker density, and the different admixture dynamics. Our simulation results indicate correct type 1 error rates of the proposed likelihood ratio tests and great impact of marker density on the power. The simulation results also indicate that the methods work well for the admixed populations derived from both hybrid-isolation and continuous gene-flowing models. Finally, we observed that the genotype-based HMM performs very similarly in power as the haplotype-based HMM when the haplotypes are known and the set of markers is highly informative.

Alleles↗
PubMed2004

The effect of connective tissue growth factor on human renal tubular epithelial cell transdifferentiation.

To investigate the role of connective tissue growth factor (CTGF) in transdifferentiation of human renal tubular epithelial cell (HKC), in vitro cultured HKC cells were divided into 3 groups: negtive control, low dose CTGF-treated group (rh CTGF, 2.5 ng/ml) and high dose CTGF-treated (rhCTGF, 5.0 ng/ml). Then the expression of alpha-smooth muscle actin (alpha-SMA) were assessed by indirect immuno-fluorescence, and the percentage of alpha-SMA positive cells were assessed by flow cytometry. RT-PCR were also performed to examine the mRNA level of alpha-SMA. Upon the stimulation of different concentrations of rhCTGF, the expression of alpha-SMA were markedly stronger than that in negative controls. The percentages of alpha-SMA positive cells were significantly higher in the stimulated groups than that of negative controls (38.9%, 65.5% vs 2.4%, P<0.01). alpha-SMA mRNA levels were also up-regulated by the stimulation of rhCTGF (P<0.01). These results suggest that CTGF can promote the transdifferentiation of human renal tubular epithelial cells towards myofibroblast (Myo-F).

Actins↗
PubMed2004

Connective tissue growth factor regulates the key events in tubular epithelial to myofibroblast transition in vitro.

Connective tissue growth factor (CTGF) has been reported to play an important role in mediating the profibrotic effects of transforming growth factor-beta (TGF-beta) in various renal diseases. To elucidate the role of CTGF in renal tubular epithelial-myofibroblast transdifferentiation, we examined the expression of alpha-smooth muscle actin (alpha-SMA), vimentin, tenascin-C, and collagen IV expression upon the stimulation of CTGF in cultured human proximal tubular epithelial cell line (HKC), and further investigated the effects of endogenous CTGF blockade on the transdifferentiation process induced by TGF-beta. It is revealed that upon the stimulation of recombinant human CTGF (rhCTGF, 2.5 or 5.0 microg/L), the expression of alpha-SMA and tenascin-C mRNA increased significantly (p<0.01), while collagen IV gene expression decreased significantly (p<0.01), all in a dose-dependent manner. The percentage of alpha-SMA-positive cells was significantly larger in the rhCTGF-stimulated groups than that in negative control (38.9%, 65.5% vs. 2.4%, respectively, p<0.01) as confirmed by flow cytometry. Both cytoplasmic and secretory tenascin-C expression was upregulated by the stimulation of rhCTGF (p<0.01). Under this condition, collagen IV secreted into the culture media was lowered markedly (p<0.01). On RT-PCR analysis, TGF-beta1 upregulated CTGF gene expression, preceding that of alpha-SMA. The alpha-SMA mRNA expression induced by TGF-beta1 was significantly inhibited by CTGF antisense oligodeoxynucleotide (ODN) transfection (p<0.01). With prolonged incubation time, CTGF antisense ODN also inhibited intracellular alpha-SMA protein synthesis, as demonstrated by indirect immuno-fluorescence. So it is concluded that CTGF could promote the transdifferentiation of human renal tubular epithelial cells towards myofibroblasts in vitro, both directly and as a downstream mediator of TGF-beta, and CTGF blockade would be a possible therapeutic target against tubulointerstitial fibrosis.

Actins↗
PubMed2004

Polyethylenimine strategies for plasmid delivery to brain-derived cells.

The introduction of effective transfection reagents has had a dramatic impact on basic scientific studies over the past decade and is methodically becoming a clinical relevant agent. An area where these agents have had little impact to date is in transfection of neuronal cells either in vivo or in vitro. The poor results, obtained with these cells, likely arise from the innate properties of the cell itself such as its post-mitotic state and its fragility to the transfection agent. In this report, we investigated the transfection efficiency of branched and linear form of polyethylenimine (PEI) for a commonly used tissue culture cell line, the human CF bronchial epithelial cell line IB3-1, rat brain-derived glial, and neuronal cell lines. In addition, the effect of reaction conditions, such as ratio of PEI/plasmid, polymer molecular weight, and shape, was addressed on the transfection effects. The results indicate that branched PEI is more effective for the brain-derived cells. It is also shown that PEI 25 is more effective for the glial cells and PEI 50-100 is more effective for the neuronal cells under the evaluation conditions.

Animals↗
PubMed2004

Comparative and evolutionary analysis of the cytochrome b sequences in cyprinids with different ploidy levels derived from crosses.

The mitochondrial cyt b genes in the allotetraploid and triploid crucian carp as well as triploid common carp were isolated and completely sequenced. Their DNA sequences were compared with those derived from the cyt b genes of the red crucian carp, Japanese crucian carp, and common carp with MEGA 1.0 software. Phylogenetic analysis revealed the sister relationships between allotetraploid and diploid red crucian carp, between the triploid crucian carp and diploid Japanese crucian carp, and between triploid common carp and diploid common carp. Our results indicated the cyt b genes in the allotetraploid, triploid crucian carp, and triploid common carp were maternally inherited. Through maternal inheritance, the cyt b gene in the F11 tetraploid displayed extremely high similarity to that in the female parent red crucian carp after 11 generations (from F1 to F11 hybrids). Since the establishment of the new tetraploid stocks has great significance in analyzing evolutionary theory of vertebrate and in improving aquaculture industry, analysis of the cyt b gene and the elucidation of the variation of the cyt b gene DNA in different cyprinids prove that cyt b is a useful genetic marker to monitor the variations in the progeny of the crosses.

Amino Acid Sequence↗
PubMed2004

[Wavefront-guided laser in situ keratomileusis for myopia].

OBJECTIVE: To compare the clinical results of wavefront-guided versus conventional LASIK surgery in the treatment of myopia. METHODS: One hundred and thirteen eyes underwent wavefront-guided LASIK (Zyoptix) and 335 eyes were received conventional LASIK surgery (Planoscan). Besides visual acuity and refractions, the higher order aberrations and contrast sensitivity are also compared after surgery. RESULTS: The postoperative refractions were not significantly different between the Zyoptix group and Planoscan group. 33.6% of Zyoptix patient and 17.0% of Planoscan patient respectively, had postoperative uncorrected visual acuity than their preoperative best corrected visual acuity. At 6 mm pupil size, the higher order RMS was increased by 100% in the Planoscan group, while in the Zyoptix group, it was increased only by 35% postoperatively. Six months after operation, the contrast sensitivity of Planoscan patients returned to their preoperative baseline. However, the Zyoptix patients had slightly better contrast sensitivity than their preoperative level. CONCLUSION: Patients undergoing Zyoptix treatment have better quality of vision after surgery than Planoscan patients.

Adult↗
PubMed2004

[The radiolabeling property of oligonucleotide with 99mTc using NHS-MAG3 as a chelator].

OBJECTIVE: To explore the radiolabeling property of oligonucleotide with 99mTc using NHS-MAG3 as a bifunctional chelator. METHODS: Three 15-base single-stranded amine-derivitized oligonucleotides, which were antisense(ASON), sense(SON) and mismatched oligonucleotides(MON) of c-myc oncogene mRNA, were coupled with NHS-MAG3 and labeled with 99mTc. The labeled oligonucleotide was purified by Sephadex G25 column chromatogram, then the stability was evaluated. The labeling efficiency of ON-MAG3 was assessed 15 days, 1 month and 2 months after storage at -20 degrees C. The binding rate of 99mTc-ON with plasma protein was measured by the trichloroacetic acid precipitation method. RESULTS: The average labeling efficiency of 99mTc-ASON, 99mTc-SON and 99mTc-ON was 68.41%, 66.24% and 69.38% respectively, and the radiochemical purity was 96.98%, 95.34% and 94.62%. 99mTc-ON was stable when placed at room temperature or incubated in human serum at 37 degrees C. The labeling efficiency of ON-MAG3 did not significantly change 2 months after storage at -20 degrees C. The plasma protein binding rate of 99mTc-ON was lower than 13%. CONCLUSION: 99mTc-ON labeled with NHS-MAG3 method showed superior radiochemical characteristics. The labeling efficiency and radiochemical purity were desirable. The label was stable in serum and the binding with plasma protein was low. 99mTc-ON could be a sort of potential radiopharmaceutical for in vivo applications.

Animals↗
PubMed2004

Role of connective growth factor in plasminogen activator inhibitor-1 and fibronectin expression induced by transforming growth factor beta1 in renal tubular cells.

BACKGROUND: Connective tissue growth factor (CTGF) contributes greatly to renal tubulointerstitial fibrosis, which is the final event leading to end-stage renal failure. This study was designed to investigate the effects of CTGF antisense oligodeoxynucleotides (ODNs) on the expressions of plasminogen activator inhibitor-1 (PAI-1) and fibronectin in renal tubular cells induced by transforming growth factor beta1 (TGF-beta1) in addition to the role of CTGF in the accumulation and degradation of renal extracellular matrix (ECM). METHODS: A human proximal tubular epithelial cell line (HKC) was cultured in vitro. Cationic lipid-mediated CTGF antisense ODNs were transfected into HKC cells. After HKC cells were stimulated with TGF-beta1 (5 microg/L), the mRNA levels of PAI-1 and fibronectin were measured by RT-PCR. Intracellular PAI-1 protein synthesis was assessed by flow cytometry. The secreted PAI-1 and fibronectin in the medium were determined by Western blot and ELISA, respectively. RESULTS: TGF-beta1 was found to induce tubular CTGF, PAI-1, and fibronectin mRNA expression. PAI-1 and fibronectin mRNA expression induced by TGF-beta1 was significantly inhibited by CTGF antisense ODNs. CTGF antisense ODNs also inhibited intracellular PAI-1 protein synthesis and lowered the levels of PAI-1 and fibronectin protein secreted into the medium. CONCLUSIONS: CTGF may play a crucial role in the accumulation and degradation of excessive ECM during tubulointerstitial fibrosis, and transfecting CTGF antisense ODNs may be an effective way to prevent renal fibrosis.

Cells, Cultured↗