Biomedical subjects

Wen Huang

Publications and source records attributed to Wen Huang.

At least 19 recordsLinked to original sources

PubMed2006

Modified glomerular filtration rate estimating equation for Chinese patients with chronic kidney disease.

The Modification of Diet in Renal Disease (MDRD) equations provide a rapid method of assessing GFR in patients with chronic kidney disease (CKD). However, previous research indicated that modification of these equations is necessary for application in Chinese patients with CKD. The objective of this study was to modify MDRD equations on the basis of the data from the Chinese CKD population and compare the diagnostic performance of the modified MDRD equations with that of the original MDRD equations across CKD stages in a multicenter, cross-sectional study of GFR estimation from plasma creatinine, demographic data, and clinical characteristics. A total of 684 adult patients with CKD, from nine geographic regions of China were selected. A random sample of 454 of these patients were included in the training sample set, and the remaining 230 patients were included in the testing sample set. With the use of the dual plasma sampling (99m)Tc-DTPA plasma clearance method as a reference for GFR measurement, the original MDRD equations were modified by two methods: First, by adding a racial factor for Chinese in the original MDRD equations, and, second, by applying multiple linear regression to the training sample and modifying the coefficient that is associated with each variable in the original MDRD equations and then validating in the testing sample and comparing it with the original MDRD equations. All modified MDRD equations showed significant performance improvement in bias, precision, and accuracy compared with the original MDRD equations, and the percentage of estimated GFR that did not deviate >30% from the reference GFR was >75%. The modified MDRD equations that were based on the Chinese patients with CKD offered significant advantages in different CKD stages and could be applied in clinical practice, at least in Chinese patients with CKD.

Algorithms↗

PubMed2006

ZNF325, a novel human zinc finger protein with a RBaK-like RB-binding domain, inhibits AP-1- and SRE-mediated transcriptional activity.

Mitogen-activated protein kinase (MAPK) signal transduction pathways are among the most widespread mechanisms of eukaryotic cell regulation. The zinc-finger-containing transcription factors have been previously revealed to be involved in the regulation of the MAPK signaling pathways. Here, we have identified a novel human zinc-finger transcriptional repressor, ZNF325, that contains a RBaK-like RB-binding domain and 15 tandem repeated C2H2 type zinc fingers. Northern blot analysis indicates that a 2.7 kb transcript specific for ZNF325 is widely expressed in all tissues examined at adult stage and in most of the embryonic tissues. Overexpression of ZNF325 in COS-7 cells inhibits the transcriptional activities of AP-1 and SRE. The deletion and RNAi analysis indicate that the C2H2 zinc finger motifs represent the basal transcriptional repressive activity. These results indicate that the ZNF325 protein may act as a novel transcription repressor in MAPK signaling pathway to mediate cellular functions.

Amino Acid Sequence↗

PubMed2006

ZNF569, a novel KRAB-containing zinc finger protein, suppresses MAPK signaling pathway.

Transcription factors play an essential role in altering gene expression. A great progress about transcription factors has been made towards the understanding of normal physiological processes, embryonic development, and human diseases. Here we report the identification and characterization of a novel KRAB-containing zinc-finger protein, ZNF569, which is isolated from a human embryonic heart cDNA library. ZNF569 encodes a putative protein of 686 amino acids. The protein is conserved across different species during evolution. Expression of ZNF569 was found in most of the examined human adult and embryonic tissues with a higher level in heart and skeletal muscles. The KRAB and ZNF motifs of ZNF569 represent potent repression domains. When ZNF569 is fused to Gal-4 DNA-binding domain and co-transfected with VP-16, ZNF569 protein suppresses transcriptional activity. Overexpression of ZNF569 in COS-7 cells inhibited the transcriptional activities of SRE and AP-1, which may be silenced by siRNA. The results suggest that ZNF569 protein may act as a transcriptional repressor that suppresses MAPK signaling pathway to mediate cellular functions.

Amino Acid Motifs↗

PubMed2006

Selective elimination of hepatic natural killer T cells with concanavalin A improves liver regeneration in mice.

BACKGROUND: Although concanavalin A (Con A) as a T cell stimulant can cause natural killer T (NKT) cell-mediated liver injury in mice and a nonhepatotoxic dose of Con A can trigger innate immune cells including NKT cells to prevent tumor metastasis in the liver, little is known about the role of Con A-primed NKT cells in liver repair. In this study, we aimed to investigate the effect of pretreatment with a nontoxic dose of Con A on subsequent liver regeneration in mice. METHODS: A nontoxic dose of Con A was injected intravenously 24 h before partial hepatectomy (PHx), which was used as a model of liver regeneration. Ratios of remnant liver mass to body weight, bromodeoxyuridine (BrdU) incorporation and proliferating cell nuclear antigen (PCNA) labeling were used to assess liver regeneration. RESULTS: Hepatic mononuclear cells were isolated and analyzed by flow cytometry. After PHx, the ratios of liver weight to body weight, PCNA-positive hepatocytes and BrdU-positive hepatocytes in Con A-pretreated mice were significantly higher than that of phosphate-buffered saline-treated mice, indicating that Con A pretreatment can accelerate liver regeneration. Flow cytometric analysis showed that NKT cells were significantly activated and selectively eliminated after the Con A administration. Moreover, NKT cells expressed more apoptosis-related molecules, Fas and Annexin V. CONCLUSIONS: Taken together, Con A accelerates liver regeneration in mice by eliminating hepatic NKT cells via activation-induced cell death.

Alanine Transaminase↗

PubMed2006

Inhibition of the ubiquitin-proteasome system: a new avenue for atherosclerosis.

BACKGROUND: The ubiquitin-proteasome system (UPS) is thought to be functionally active in atherosclerosis (AS) lesions. Aspirin was found to be a potent inhibitor of the UPS in some tumour studies; however, its effect on AS remains to be demonstrated in vivo. METHODS: New Zealand rabbits were placed on a normal diet (N) or on a normal diet with aspirin (NI) or on an atherogenic diet without (H) or with aspirin (HI) for 12 weeks. Proteasome activity, concentrations of plasma lipids and levels of peroxidation were determined. Ubiquitin/ubiquitin-conjugates (Ub), IkappaBalpha, phosphorylated IkappaB (pIkappaBalpha) and p65 were investigated by Western blotting or immunochemistry. RESULTS: Concentrations of plasma lipids and peroxidation levels were higher in H or HI vs. N or NI. Histological analysis showed that atheroma was increased in H. Ub and IkappaBalpha were mainly localised in subendothelium and media vascular smooth muscle cells. Western blots revealed that Ub, IkappaBalpha, and pIkappaBalpha were increased, whereas p65 was lower in HI vs. H. The activity of the 20S proteasome was functionally active in H vs. N, NI or HI, while the 26S proteasome was not affected in any of the groups. CONCLUSIONS: Aspirin can attenuate the pathogenesis of atheroma formation, the degradation of IkappaBalpha and pIkappaBalpha, and lower the expression of p65, indicating that its therapeutic effects on AS may be via inhibition of the UPS.

Animals↗

PubMed2005

[Effects of combined use of curcumin and catechin on cyclooxygenase-2 mRNA expression in dimethylhydrazine-induced rat colon carcinogenesis].

OBJECTIVE: To examine the effect of combined use of curcumin and catechin on the number of aberrant crypt foci (ACF) and expression levels of cyclooxygenase-2 (COX-2) mRNA in rat colon carcinogenesis. Methods Dimethylhydrazine (DMH)-induced rats colon carcinogenesis model was used for evaluation of the synergistic inhibitory effect between curcumin and catechin in light of ACF formation and tumor incidence. COX-2 mRNA expression was also detected in rat colon carcinogenesis. RESULTS: Curcumin, catechin and their co-treatment caused significant inhibition of DMH-induced ACF and colon carcinogenesis as compared with untreated DMH-induced rat models (P<0.01). Co-treatment with curcumin and catechins caused greater inhibition of DMH-induced ACF and colon carcinogenesis than the single use of curcumin or catechin (P<0.05). A synergistic inhibitory effect between curcumin and catechin on the expression of COX-2 mRNA was observed in the early stage of rat colon carcinogenesis but not in colon tumor tissues. CONCLUSION: Curcumin and catechin have synergistic effect on ACF and COX-2 mRNA expression in rat colon carcinogenesis, suggesting their potential value in the prevention of human colon cancers.

1,2-Dimethylhydrazine↗

PubMed2005

[In vitro bromodeoxyuridine labeling of rat bone marrow-derived mesenchymal stem cells].

OBJECTIVE: To study the optimal dosage and timing for bromodeoxyuridine (BrdU) labeling of rat bone marrow-derived mesenchymal stem cells (MSCs) in vitro. METHODS: Bone marrow-derived MSCs of SD rats were cultured in vitro routinely and the sixth passage was taken for identification of specific surface antigens by flow cytometry. Before reaching cell confluence, the purified MSCs were incubated with BrdU at different concentrations (5, 10, and 15 micromol/L) for different incubating time (3, 12, 24, 36, 48, and 72 h) with 10 micromol/L BrdU, to identify the optimal BrdU concentration and incubating time for cell labeling. Immunohistochemistry was performed to calculate the labeling index (LI). RESULT: Flow cytometry showed that MSCs expressed CD29 and CD44 but not CD11b or CD45. Incubation of the MSCs with BrdU at 10 micromol/L and for an optimal length of 48 h appeared to achieve the highest LI, both of which exceeded 98%, with the labeling identifiable in five consecutive passages. CONCLUSIONS: The continually passaged cells are MSCs, the incubation of which with 10 micromol/L BrdU for 48 h may achieve a LI over 98% without producing obvious cell damages. The results suggest that BrdU labeling provides a feasible means for a dynamic in vivo observation of the survival, growth and differentiation of the implanted MSCs.

Animals↗

PubMed2005

[Effects of granulocyte colony-stimulating factor on focal cerebral ischemia-reperfusion injury in rats].

OBJECTIVE: To study the therapeutic effects of granulocyte colony-stimulating factor (G-CSF) on focal cerebral ischemia-reperfusion injury in rats. METHODS: Adult male SD rats were subjected to transient (2 h) middle cerebral artery occlusion (MCAO) and scored 48 h later for such neurological functions as spontaneous movement, paresis, forelimb motor function, climbing ability, pain sensation, and position sense. Twenty rats with the total score less than 12 were divided equally into two groups to receive daily subcutaneous injection of 20 microg/kg of G-CSF for 19 days or the same dose of saline injection (control group). The rats in the two groups were also given intraperitoneal injection of Brdu10 mg/kg for 19 days. The neurological functions of the rats in both groups were examined on a weekly basis after MCAO and on day 21, the rats were killed to prepare frozen sections of the brain tissues for double immunohistochemical staining with Brdu and glial fibrillary acidic protein antibody to identify the neural cells newly evolved from the stem cells. RESULTS: The rats in G-CSF group showed better neurological function recovery than the control rats 3 weeks after MCAO (P<0.05). Obvious regeneration of the neural cells was observed around the infarction area in the rats receiving G-CSF treatment. CONCLUSION: G-CSF promotes neurological function recovery and neural cell regeneration after cerebral infarction in rats and can be effective for intervention of focal cerebral ischemia-reperfusion injury.

Animals↗

PubMed2005

[Preparation oral liposome-encapsulated recombinant Helicobacter pylori heat shock protein 60 vaccine for prevention of Hp infection].

OBJECTIVE: To prepare oral liposome-encapsulated recombinant Helicobacter pylori (Hp) heat shock protein 60 (Hsp60) vaccine and investigate its effect against Hp infection in mice. METHODS: The recombinant vector PET-22(+)/Hsp60 was transformed into BL21(DE3) E.coli. The recombinant protein was purified with Ni-NTA agrose resin and the oral liposome-encapsulated vaccine was prepared with phosphatidyl choline and cholesterols using film method, with the size distribution of the folate liposomes measured by transmission electronic microscopy. BALB/c mice were divided into 5 groups and immunized by intragastric administration of PBS, liposome, rHsp60 plus choleratoxin (CT), liposome-encapsulated rHsp60, and liposome-encapsulated rHsp60 plus CT, respectively, given once a week for 4 weeks. All the mice were challenged by Hp for 3 times within two weeks following the last immunization and sacrificed 3 weeks after the last challenge. Hp detection was performed by fast urease test. Semi-quantitative assessment of the bacterial colonization density observation of the inflammation severity and gastric histopathology were carried out. RESULTS: The soluble expression product accounted for 27% of the total bacterial protein. The purity of recombinant fusion protein was about 95% after purification. The mean size of the folate liposomes was 0.7+/-0.4 mum. PBS or liposome alone showed no immune-enhancing effect, and rHsp60 plus CT, liposome-encapsulated rHsp60 and liposome-encapsulated rHsp60 plus CT had the protective rates against Hp infection of 73.3%, 66.7% and 86.7%, respectively. The latter 3 preparations effected significantly reduced Hp infection and alleviated the inflammation in the gastric mucosa of the mice challenged with Hp. CONCLUSION: The oral liposome may serve as a potential adjuvant for Hp vaccine in preventing Hp infection.

Animals↗

PubMed2004

ZNF322, a novel human C2H2 Kruppel-like zinc-finger protein, regulates transcriptional activation in MAPK signaling pathways.

Cardiac differentiation involves a cascade of coordinated gene expression that regulates cell proliferation and matrix protein formation in a defined temporal-spatial manner. The C(2)H(2) zinc finger-containing transcription factors have been implicated as critical regulators of multiple cardiac-expressed genes and are important for human heart development and diseases. Here we have identified and characterized a novel zinc-finger gene named ZNF322 using degenerated primers from a human embryo heart cDNA library. The gene contains four exons and spans 23.2kb in chromosome 6p22.1 region, and transcribes a 2.7kb mRNA that encodes a protein with 402 amino acid residues. The predicted protein contains 9 tandem C(2)H(2)-type zinc-finger motifs. Northern blot analysis shows that ZNF322 is expressed in every human tissue examined at adult stage and during embryonic developmental stages from 80 days to 24 weeks. When overexpressed in COS-7 cells, ZNF322-EGFP fusion protein is detected in the nucleus and cytoplasm. Reporter gene assays show that ZNF322 is a transcriptional activator. Furthermore, overexpression of ZNF322 in COS-7 cells activates the transcriptional activity of SRE and AP-1. Together, these results suggest that ZNF322 is a member of the zinc-finger transcription factor family and may act as a positive regulator in gene transcription mediated by the MAPK signaling pathways.

Amino Acid Sequence↗

PubMed2004

Relationship between plasma D-dimer levels and clinicopathologic parameters in resectable colorectal cancer patients.

AIM: To assess the clinical significance of the D-dimer levels and the relationship between plasma D-dimer levels and clinicopathologic parameters in operable colorectal cancer patients. METHODS: The plasma levels of D-dimer were measured pre- and postoperatively in 35 patients with colorectal cancer, and 30 healthy subjects served as controls by the method of quantitative enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean preoperative plasma levels of D-dimer in the patients with colorectal cancer (1.06+/-0.24 mg/L) were significantly higher than those of controls (0.33+/-0.12 mg/L,P<0.01). The D-dimer levels were remarkably elevated on the 1st day after operation (1.22+/-0.55 mg/L, P<0.01). On the 3rd day the level of D-dimer began to stepwise descend and on the 14(th) day nearly returned to control level. The preoperative levels of D-dimer were significantly correlated with the lymph node metastasis and Dukes stage but had no association with tumor location and the degree of differentiation. A stepwise increase in the mean D-dimer levels was found with increase of the tumor stage. CONCLUSION: Hypercoagulation and higher fibrinolytic activities occur in patients with colorectal cancer. The operative trauma could enhance the fibrinolysis in the patients with colorectal cancer. The measurement of preoperative D-dimer levels is considered to be useful for predicting lymph node metastasis and stage of colorectal cancer.

Adult↗

PubMed2004

[Dynamic changes in the expressions of myogenic regulatory factors MyoD and myogenin during repair of muscle injury].

OBJECTIVE: To observe the dynamic changes in the expressions of myogenic regulatory factors MyoD and myogenin during the repair of injured muscle. METHODS: Muscular injury model was established by local injection of bupivacain, and at different time points following the injection, the gastrocnemius muscles were collected for preparation of cryosections. HE staining was performed for examination of the pathological changes in the injured muscles, and the expressions of MyoD and myogenin were detected by SABC. RESULTS: MyoD-positive nuclei began to appear 18 h after muscle injury, reaching the peak till 48 h after the injury. Myogenin-positive nuclei appeared 24 h after muscle injury and peaked at 72 h. CONCLUSIONS: MyoD and myogenin play a role in muscle regeneration after muscle injury, and they may serve as the indexes to identify muscle precursor cells and mark muscle regeneration process.

Animals↗

PubMed2004

[Carrier detection of Duchenne/Becker muscular dystrophy in Chinese families by microsatellite analysis].

OBJECTIVE: To screen and detect the female carriers from the DMD/BMD family members for prenatal or preimplantation genetic diagnosis. METHODS: For the detection of DMD/BMD carriers from 27 family members in 4 families, PCR to five microsatellite markers(located in 5' terminus and intron 44, 45, 49, 50) and analysis of the short tandem repeat(STR) sequence polymorphism with the use of genescan were implemented. RESULTS: Six of the 17 female members were obligate DMD gene carriers according to the haplotype analysis of the results of the genescan, which conformed with the pedigree analysis. Besides, the authors detected five carriers and five normal females in these families with the use of the haplotype analysis only. The most polymorphic locus was STR 49, and the least was STR 50. CONCLUSION: The STR haploid linkage analysis using (CA)n repeats within the human dystrophin gene is a rapid,accurate, objective method and is well suited for routine use in clinical laboratories engaged in DMD/BMD linkage analysis for the detection of carrier.

Female↗

PubMed2004

[Single cell analysis of some deletion in dystrophin gene exons and gender determination by 3-plex nested PCR].

OBJECTIVE: To set up a technique of single lymphocytes 3-plex nested PCR for dystrophin and SRY gene, and to evaluate the possibility of using this technique for preimplantation genetic diagnosis(PGD) of deleted Duchenne muscular dystrophy (DMD) with family history. METHODS: Fifty single lymphocytes of a normal male and fifty of a normal female were obtained for detecting dystrophin gene(exon 51, exon 19, exon 48) and SRY gene by 3-plex nested PCR. RESULTS: In the group of exon 51/exon 19/SRY, the amplification rates of exon 51, exon 19 and SRY in male were 96%, 94% and 94%; the amplification rates of exon 51 and exon19 in female were 94% and 94%, respectively. In the exon 48/exon 19/SRY group, the amplification rates of exon 48, exon 19 and SRY in male were 92%, 90% and 94%, the amplification rates of exon 48, exon 19 in female were 94% and 92%, respectively. CONCLUSION: The technique of single lymphocytes 3-plex nested PCR for dystrophin and SRY gene established in this study is highly sensitive, specific and reliable, and is suitable for PGD of deleted DMD with family history.

Dystrophin↗

PubMed2004

[Brain-derived neurotrophic factor induces rat bone marrow stromal cells to differentiate into neuron-like cells in vitro].

OBJECTIVE: To investigate brain-derived neurotrophic factor (BDNF)-induced differentiation of rat bone marrow stromal cells (MSCs) into neuron-like cells in vitro and observe its neuroprotective effect of BNDF on the differentiated cells, which might provide the better seed cells for treatment of nervous system diseases. METHODS: The fifth-passage MSCs were induced by BDNF and 2-mercapto ethanol beta-ME respectively, 1, 3 and 6 h after which the induced neuron-like cells were counted and compared. At 3 h, the neuron-like cells were identified by the immunocytochemical staining, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: The two induced cells both displayed neuronal morphologies with long and multipolar cell projections, but BDNF-induced cells survived for a longer time than beta-ME-induced ones. The results of immunocytochemical staining showed that the two neuron-like cells expressed nestin, neuron-specific enolase (NSE), neurofilament (NF), microtubule-associated protein (MAP-2), but not glial fibrillary acidic protein (GFAP). RT-PCR detected mRNA-positive NSE, NF and MAP-2 in the induced cells, with also mild positive GFAP mRNA. Western blotting identified also NSE expression in these neuron-like cells. CONCLUSION: BDNF alone may induce rat MSCs to differentiate into neuron-like cells in vitro, which have longer lifetime to better serve the purpose of transplantation and gene therapy for nervous system diseases.

Animals↗

PubMed2003

Treatment of 522 patients with Nevus of Ota with Q-switched Alexandrite laser.

OBJECTIVE: To evaluate the clinical response of Nevus of Ota to Q-switched Alexandrite laser, and analyze factors that influence the treatment outcome. METHODS: A total of 522 patients treated with Q-switched Alexandrite laser were included in the study. Single and multiple variate analyses of various factors were performed. RESULTS: Satisfactory result was observed in all patients, none of whom developed scarring. Clinical response was improved with additional treatment sessions. The clinical response of the 20 - 27-week treatment interval group was significantly better than that of the 12 - 19-week interval group, but showed no significant difference as compared with both the 28 - 35 and > or = 36-week interval group. Zygomatic, buccal and frontal areas showed better response than ocular and temporal areas. Treatment session, interval, and fluence were significant factors identified by multivariate analysis. CONCLUSIONS: Q-switched Alexandrite laser is an ideal method for treating Nevus of Ota without injury. The number of treatment sessions is more important than interval or fluence.

Adolescent↗

PubMed2003

[A novel method for fabrication of tissue microarray].

BACKGROUND & OBJECTIVE: Tissue chip (tissue microarray, TMA) is one of the most important biochip techniques, just following the gene chip and the protein chip, which is one of the most important functional genomics and proteomics research methods in the post-genomic era. However, the present TMA technology has certain shortcomings, such as lack of advanced instruments, tedious procedure, and low sampling accuracy, etc. This new method was designed to improve the technology of TMA. METHODS: A common microscope was installed with a special holing needle, a sampling needle, and a proper box to fix paraffin blocks on the microscope carrier. With the precise mechanical control of microscope, the holing procedure on the recipient paraffin blocks and sampling procedure of core tissue biopsies were performed with the re-equipped microscope. The precise observation and localization of sampling regions were also performed using the same microscope equipped with a stereoscope. RESULTS: The new method simplified TMA procedure, and the whole process of holing, locating, and sampling was performed with the same instrument on the same platform. The single-use holing and sampling needles were first applied to maintain higher accuracy and to avoid the tissue remains and contamination among different samples. And high-qualified tissue chips of colorectal tumors were produced successfully by the new method. CONCLUSION: Using the re-equipped common microscope to fabricate tissue microarrays is a simple, reliable, cost-effective,and well-applicable technique.

Histocytological Preparation Techniques↗

PubMed2003

Effect of Q-switched Alexandrite laser irradiation on epidermal melanocytes in treatment of Nevus of Ota.

OBJECTIVE: To investigate injury to epidermal melanocyte by Q-switched Alexandrite laser. METHODS: Multiple biopsies were performed on 5 patients with nevus of Ota from before irradiation to 1 year after irradiation. Fourteen specimens were obtained for light microscopy, and 17 for transmission electron microscopy. RESULTS: Melanosomes in epidermal melanocytes were both smaller in size and fewer in number than those in dermal melanocytes. Immediately after irradiation, focal extracellular vacuoles of the basal layer could be observed under light microscopy. Most epidermal melanocytes underwent mild or moderate injury in the form of vacuolated melanosomes, swollen mitochondria, dilation of endoplasmic reticulum, and expansion of extracellular space, retaining intact cell membranes. Normal structures were restored 5 months to 1 year after irradiation, with no depigmentation or hyperpigmentation as seen by light microscopy. CONCLUSION: Injury of melanosomes in epidermal melanocytes is reversible.

Adolescent↗