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Biomedical subjects

Hong Yu

Publications and source records attributed to Hong Yu.

At least 73 records · Page 4Linked to original sources
PubMed2005

[Preparation and identification of hammerhead ribozyme in vitro against caspase-12 mRNA fragments].

OBJECTIVE: To design and synthesize ribozymes targeting 138 and 218 sites of the mRNA nucleotide of mouse caspase-12, a key intermedium of ER stress mediated apoptosis, and to identify their activities through in vitro transcription and cleavage. METHODS: The mouse caspase-12 gene fragment was obtained by RT-PCR and cloned into the PGEM-T vector under the control of T7 RNA polymerase promoter. The transcription product of the target was labeled with a-32P UTP, while ribozymes were not labeled. Ribozyme and target RNA were incubated for 90 min at 37 degree C in a reaction buffer to perform the cleavage reaction. RESULTS: It was found that under a condition of 37 degree C, pH 7.5 and with Mg2+ in a concentration of 10 mmol/L, Rz138 and Rz218 both cleaved targets at predicted sites, and the cleavage efficiency of Rz138 was 100%. CONCLUSION: Rz138 and Rz218 prepared in vitro possess the perfect specific catalytic cleavage activity. Rz138 has excellent cleavage efficiency. It may be a promising tool to prevent ER stress induced apoptosis through catalytic cleavage of caspase-12 mRNA in vivo. It also can be used to verify whether caspase-12 is necessary in ER stress induced apoptosis.

Animals↗
PubMed2005

[Changes of fibronectin and type IV collagen expression in cultured rat mesangial cells transfected with Smad 2 vector].

OBJECTIVE: To study the changes of fibronectin (FN) and type IV collagen (ColIV) expression in cultured rat mesangial cells (MsC) transfected with Smad 2 vector and to investigate the molecular mechanism of glomerular extracellular matrix accumulation in glomerulosclerosis via transforming growth factor-beta (TGF-beta)/Smad signal pathway. METHODS: Smad 2 vector was transfected into MsC by calcium phosphate. Western blot analysis was used to detect Smad 2 protein. The expression of FN and ColIV proteins and their mRNAs was determined by Western blot and reverse transcriptase-polymerase chain reaction respectively. RESULTS: Four MsC clones (T-12, T-31, T-35, T-40) with Smad 2 overexpression were established. The expression of FN and ColIV was significantly increased at mRNA and protein levels in two (T-12, T-31). Compared with controls, the expression of FN proteins and mRNAs in these two clones was 2.4 times (P < 0.05) and 2.7 times (P < 0.05) higher respectively. The expression of ColIV proteins and mRNAs was 2.9 times (P < 0.01) and 3.3 times (P < 0.01) higher respectively. CONCLUSIONS: It is postulated that Smad 2 in TGF-beta/Smad signal pathway is important in promoting the accumulation of FN and ColIV in sclerotic glomeruli of diseased kidneys.

Animals↗
PubMed2005

[Study on the current situation and influential factors of child neglect among aged 3-6 year-olds in the urban areas of China].

OBJECTIVE: Children aged 3 - 6 years in the urban areas of China were surveyed for the first time to find out the state of child neglect (CN) as well as the major relevant risk factors so as to provide evidence for developing intervention measures. METHODS: 1163 children (of whom 49.6% were males and 4.5% were minority nationality) were randomly sampled under multistage stratification, from 25 cities which representing 15 provinces of China. Based on the Child Neglect Norms used by China, prevalence of CN was identified and SPSS-Windows 11.0 was employed for statistical analysis. Scores, frequency/degrees, age, sex and 5 types (physical, emotional, educational, medical and safety) of CN on every group of the regions, were calculated. Multifactorial analysis was conducted through Binary Logistic Regression and multiple linear regression to determine the relevant risk factors. RESULTS: (1) The average degree of CN for the 3 - 6 year-olds was 42.2, with its prevalence as 28.0%. Degrees of CN for the groups of 3, 4, 5, 6-year-olds were 41.7, 42.2, 42.1 and 43.1 (F = 0.988, P > 0.05), with frequencies of 25.0%, 25.3%, 27.9% and 35.4% (chi(2) = 4.798, P > 0.05), respectively. Degrees for CN in males and females were 42.7 and 41.8 (F = 2.502, P > 0.05) with the frequencies as 32.6% and 23.7% (chi(2) = 6.585, P < 0.05), respectively. Degrees of CN for the five types were 39.4-43.4 with the frequencies as 5.1%-12.9%, respectively. No significant difference was found in the frequency of the types (with an exception on 'physical neglect') between males and females (P > 0.05). The highest frequency (42.9%) of CN was seen in the single-parent families and the lowest in large family with three generations (25.5%). (2) According to monofactorial chi(2) test, the possible risk factors of CN would include: educational background, occupation and decrease of income of the parents during last year, etc. (3) Binary Logistic regression analysis showed that the influential factors to the occurrence of CN would include: father's educational background, sex of the child and mother's occupation, etc. (4) Multiple linear regression showed that the influential factors to the degree of CN were: family structure, number of supporting family members, relationship between parents and children, etc. CONCLUSION: The degree and frequency of CN among children aged 3 to 6 in the urban areas of China were high but similar among the four age groups. Male children had a higher frequency of neglect than females, but with similar degree. Children in single-parent families had the highest frequency. The major influential factors of CN would include: educational background, occupation, family structure, family income of the parents which were similar to the results reported from foreign literature.

Child↗
PubMed2005

[Cold stress causes early apoptosis in caudal fin cells of Colossoma brachypomum].

CBT cell line developed from a warm-water fish Colossoma Brachypomum,was used to evaluate the effects of cold stress on fish cells. Cell viability was measured by Thiazolyl blue (MTT) method and cellular ultrastructure was examined under transmission electron microscope. Externalization of phosphatidylserine(PS) and mitochondrial membrane potential(MMP) were monitored with confocal laser scanning microscope. Results showed that cell viability and MMP decreased in a time-dependent manner, and the early events of apoptosis such as chromatin condensation, margination and PS externalization occurred, when the cells were exposed to 10 degrees C. It suggested that low temperature (10 degrees C) could induce apoptosis in Colossoma Brachypomum CBT cells.

Animals↗
PubMed2005

[Screening for new binding proteins which interact with BM2 of influenza B virus with yeast two-hybrid system].

OBJECTIVE: To explore the role of BM2 protein in the life cycle of influenza B virus. METHODS: The authors screened human kidney MATCHMAKER cDNA library for new binding partners of BM2 of influenza B virus by using the yeast two hybrid system with truncated BM2 (26-109 aa) as the bait. RESULTS: Six positive plasmids encoding N-acetylneuraminate pyruvate lyase, angiopoietin 3, zinc finger protein 251, ribosomal protein S20, protein arginine N-methyltransferase 1 variant 1 (PRMT) and transcription factor-like 1 (TCFL1) were obtained. CONCLUSION: The results suggest that BM2 may play an important role in the life cycle of influenza B virus.

Angiopoietin-Like Protein 1↗
PubMed2005

[Caspase-12 expression and activation in the pathogenesis of acute hepatic failure induced by lipopolysaccharide and D-galactosamine].

OBJECTIVE: To study the role of caspase-12 expression on hepatocyte apoptosis in an experimental model of acute hepatic failure (AHF). METHODS: A mouse experimental model of AHF was developed by intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-Gal). Hepatocyte apoptosis was examined by DNA agarose gel and liver pathology. Caspase-12 mRNA expression in liver was detected by reverse transcriptase PCR (RT-PCR) method. The expression of caspase-12, GRP78 proteins in livers was determined by Western blot. RESULTS: Caspase-12 mRNA expression in the livers increased significantly from 5 to 7 hours after administration of LPS and D-Gal. Typical manifestation of hepatocyte apoptosis appeared at 5 hours after the drug administration. After 5 hours the level of serum ALT and AST were remarkably increased, and they reached the peak at 7 hours. The expression of procaspase-12 protein decreased obviously at 7 hours. Seven hours after the drug administration, hepatocyte apoptosis and necrosis both started. The marker of endoplasmic reticulum (ER) stress, Bip/GRP78 was activated during the development of hepatocyte apoptosis. The level of Bip/GRP78 protein was gradually increased at 5 hours after the drug induction. CONCLUSION: Hepatocyte apoptosis plays an important role in the pathogenesis of AHF. Caspase-12 induced ER stress involves in hepatocyte apoptosis. It suggests that inhibition of caspase-12 activation might be a potential strategy in the treatment of AHF in the future.

Animals↗
PubMed2005

[Effect of interferon alpha on liver fibrosis in patients with chronic hepatitis B].

OBJECTIVE: To observe the histological changes in the fibrotic and inflammatory tissues in response to interferon alpha treatment in patients with chronic viral hepatitis B. METHODS: Sixteen patients with chronic viral hepatitis B in S3-S4 stages established by pathological examination were treated with interferon alpha for 6-9 months, and the degree of liver fibrosis and inflammation were examined 3 times during the treatment. The expression of Fas, transforming growth factor beta1 (TGFbeta1) and HBcAg in the liver tissues were detected by immunohistochemistry, and DNA fragmentation was examined by TUNEL assay. The levels of the serum markers for liver fibrosis and liver function were also measured. RESULTS: Patients with liver fibrosis in S3-S4 stages had high pathological expression of Fas and TGFbeta1 with severe DNA damage in the liver tissues. After 3 months of interferon therapy, the expression of Fas and TGFbeta1 were lowered (P<0.05), and further treatment till 3-9 months resulted in gradual decrease in the degree of hepatic fibrosis and cell apoptosis (P<0.05), with improved serum liver fibrosis indices and liver function. CONCLUSION: Interferon alpha may alleviate liver fibrosis and suppress cell apoptosis in patients in S3-S4 stages after a 6- to 9-month continuous treatment.

Adult↗
PubMed2005

[Inhibition of mouse hepatocyte apoptosis by anti-caspase-12 small interfering RNA].

OBJECTIVES: To study the inhibition of primary mouse hepatocyte apoptosis by small interfering RNA (siRNAs) against caspase-12. METHODS: The Balb/c mouse primary hepatocytes were isolated in situ with two-step liver perfusion with 0.5 g/L collagenase type IV, and apoptosis were induced with 4 micromol/L thapsigargin (TG). The three kingds of siRNAs targeting different gene sites (130, 214, 521) were synthetized chemically. The single-stranded RNAs were annealed to produce double-stranded siRNAs, then the mouse primary hepatocytes were transfected by oligofectamine package. The inhibition of caspase-12 was analyzed with RT-PCR and Western-blot. The viable hepatocytes following the induction of apoptosis were evaluated with MTT. RESULTS: All the three kinds of siRNAs could obviously inhibit normal mouse hepatocyte caspase-12 mRNA. The siRNA (214) were more effective than the other two when the concentration was 100 nmol/L. The caspase-12 mRNA expression was inhibited by 52.08%, while that of siRNA (521) was 30.73% (t=4.30, P <0.05). However when the concentration was 200 nmol/L, the inhibitions were similar (88.07%, 86.22% and 89.41% respectively). siRNA (214) could downregulate the expression of apoptotic hepatocytes procaspase-12 by 51.43% ( t=4.30, P <0.01). Contrasted with apoptotic hepatocytes, the cell activity, which was analyzed with MTT, increased by 48.76% (t=2.23, P <0.01). CONCLUSION: siRNAs could effectively downregulate the expression of caspase-12 at mRNA and protein levels and prevent mouse primary hepatocytes from apoptosis.

Animals↗
PubMed2005

Question analysis for biomedical question answering.

We are developing a biomedical question answering system. This paper describes our system's architecture and our question analysis component. Specifically, we have explored the use of various supervised machine learning approaches to filter out unanswerable questions based on physicians' annotations.

Artificial Intelligence↗
PubMed2004

dPak is required for integrity of the leading edge cytoskeleton during Drosophila dorsal closure but does not signal through the JNK cascade.

The Pak kinases are effectors for the small GTPases Rac and Cdc42 and are divided into two subfamilies. Group I Paks possess an autoinhibitory domain that can suppress their kinase activity in trans. In Drosophila, two Group I kinases have been identified, dPak and Pak3. Rac and Cdc42 participate in dorsal closure of the embryo, a process in which a hole in the dorsal epidermis is sealed through migration of the epidermal flanks over a tissue called the amnioserosa. Dorsal closure is driven in part by an actomyosin contractile apparatus at the leading edge of the epidermis, and is regulated by a Jun amino terminal kinase (JNK) cascade. Impairment of dPak function using either loss-of-function mutations or expression of a transgene encoding the autoinhibitory domain of dPak led to disruption of the leading edge cytoskeleton and defects in dorsal closure but did not affect the JNK cascade. Group I Pak kinase activity in the amnioserosa is required for correct morphogenesis of the epidermis, and may be a component of the signaling known to occur between these two tissues. We conclude that dorsal closure requires Group I Pak function in both the amnioserosa and the epidermis.

Amino Acid Sequence↗
PubMed2004

A draft sequence for the genome of the domesticated silkworm (Bombyx mori).

We report a draft sequence for the genome of the domesticated silkworm (Bombyx mori), covering 90.9% of all known silkworm genes. Our estimated gene count is 18,510, which exceeds the 13,379 genes reported for Drosophila melanogaster. Comparative analyses to fruitfly, mosquito, spider, and butterfly reveal both similarities and differences in gene content.

Algorithms↗
PubMed2004

Impaired agonist-dependent myosin phosphorylation and decreased RhoA in rat portal hypertensive mesenteric vasculature.

The purpose of the present study was to examine the effects of portal hypertension on agonist-induced myosin phosphorylation and RhoA expression in vascular smooth muscle. A possible link to cAMP-dependent events was also examined. Portal hypertension was produced by stenosis of the portal vein. Vessel segments were treated with or without 50 microM of the PKA inhibitor Rp-cAMPS for 30 min and subsequently stimulated with 10(-4) M phenylephrine. Myosin regulatory light-chain phosphorylation was detected by immunoblotting. Total RNA from first-order mesenteric arteries and portal veins was isolated and amplified by RT-PCR using RhoA and GAPDH primers. RhoA protein expression was also measured in first-order mesenteric arteries using Western blot analysis. Myosin phosphorylation in maximally stimulated first-order mesenteric arteries was significantly lower in portal hypertensive animals (19.9 +/- 2.86%) when compared with sham-operated control (43.8 +/- 3.53%). Inhibition of PKA selectively increased myosin phosphorylation to 34.7 +/- 4.18%. Rp-cAMPS did not affect the phosphorylation of the portal veins or superior mesenteric arteries. RhoA mRNA and membrane-associated RhoA protein expression in portal hypertensive first-order mesenteric arteries were significantly lower when compared with controls. Acute inhibition of PKA had no effect on RhoA mRNA expression. However, it restored membrane-associated RhoA protein expression in portal hypertensive vessels to control levels. The results suggest that reductions in membrane-associated RhoA expression, which appear to be regulated by cAMP-dependent events, lead to reduced myosin phosphorylation and may underlie the reduced vasoconstrictor effectiveness in the resistance vasculature of portal hypertensive intestine.

Animals↗
PubMed2004

[Laparoscopic liver resection for benign liver tumors].

OBJECTIVE: To assess the feasibility, safety, and outcome of laparoscopic liver resection for benign liver tumors. METHODS: Fourteen patients with benign liver tumors, including 11 cases of hepatic hemangioma, 1 case of hepatic focal nodular hyperplasia, 1 case of hepatic granulomatous inflammation, and 1 case of liver cyst with hyaline degeneration and calcification underwent laparoscopic liver resection by PMOD. RESULTS: Hepatectomy was performed successfully under laparoscope in these 14 patients. There was no conversion to open approach, no postoperative mortality and no postoperative complication. The mean postoperative hospital stay was 6.4 days without recurrence. CONCLUSION: Laparoscopic liver resection of benign liver tumors by PMOD is feasible and safe for patients with symptomatic and undetermined hepatic tumor, and is applicable in hepatic hemangioma complicated with cholecystitis.

Adult↗
PubMed2004

Using protein expressions to predict survival in clear cell renal carcinoma.

PURPOSE: An accurate system for predicting survival for patients with solid tumors will allow for better patient selection for both established and novel therapies. We propose a staging system for clear cell variants of renal cell carcinoma (RCC) that includes molecular predictors and standard clinical predictors such as tumor-node-metastasis (TNM) stage, histological grade, and performance status (PS). EXPERIMENTAL DESIGN: A custom tissue array was constructed using clear cell RCC from 318 patients, representing all stages of localized and metastatic RCC, and immunohistochemically stained for molecular markers Ki67, p53, gelsolin, CA9, CA12, PTEN, EpCAM, and vimentin. We present a strategy for evaluating individual candidate markers for prognostic information and integrating informative markers into a multivariate prognostic system. RESULTS: The overall median follow-up and the median follow-up for surviving patients were 28 and 55 months, respectively. A prognostic model based primarily on molecular markers included metastasis status, p53, CA9, gelsolin, and vimentin as predictors and had high discriminatory power: its statistically validated concordance index (C-index) was found to be 0.75. A prognostic model based on a combination of clinical and molecular predictors included metastasis status, T stage, Eastern Cooperative Oncology Group PS, p53, CA9, and vimentin as predictors and had a C-index of 0.79, which was significantly higher (P < 0.05) than that of prognostic models based on grade alone (C = 0.65), TNM stage alone (C = 0.73), or the University of California Los Angeles integrated staging system (C = 0.76). CONCLUSIONS: Protein expressions obtained using widely available technology can complement standard clinical predictors such as TNM stage, histological grade, and PS.

Adenocarcinoma, Clear Cell↗
PubMed2004

Optimizing the quadruple-potential waveform for the pulsed amperometric detection of neomycin.

Determination of neomycin is important for quality control of the pharmaceutical preparation. A quadruple-potential waveform used for pulsed amperometric detection of neomycin was investigated. The waveform cleans the electrode by application of a potential more negative than the potential limit to avoid the formation of gold oxide during applying positive potential to clean gold electrode, thus decreasing the dissolution resulting recession of the gold working electrode within gold oxide formation/reduction cycles in the triple-potential waveform. Waveform parameters were optimized to maximize the signal-to-noise ratio (S/N). The detection limit of neomycin B is lower than 0.01 microg/ml. The linearity of framycetin (plotted as peak area of neomycin B) ranges from 0.05 to 100 microg/ml with correlation coefficient 0.9998. R.S.D. (n = 60) of the peak area of neomycin B is lower than 2%. The quadruple-potential waveform shows low detection limits and long-term reproducibility.

Chromatography, Liquid↗
PubMed2004

Characterization and enrichment of hepatic progenitor cells in adult rat liver.

AIM: To detect the markers of oval cells in adult rat liver and to enrich them for further analysis of characterization in vitro. METHODS: Rat model for hepatic oval cell proliferation was established with 2-acetylaminofluorene and two third partial hepatectomy (2-AAF/PH). Paraffin embedded rat liver sections from model (11 d after hepatectomy) and control groups were stained with HE and OV6, cytokeratin19 (CK19), albumin, alpha fetoprotein (AFP), connexin43, and c-kit antibodies by immunohistochemistry. Oval cell proliferation was measured with BrdU incorporation test. C-kit positive oval cells were enriched by using magnetic activated cell sorting (MACS). The sorted oval cells were cultured in a low density to observe colony formation and to examine their characterization in vitro by immunocytochemistry and RT-PCR. RESULTS: A 2-AAF/PH model was successfully established to activate the oval cell compartment in rat liver. BrdU incorporation test of oval cell was positive. The hepatic oval cells coexpressed oval cell specific marker OV6, hepatocyte-marker albumin and cholangiocyte-marker CK19. They also expressed AFP and connexin 43. C-kit, one hematopoietic stem cell receptor, was expressed in hepatic oval cells at high levels. By using c-kit antibody in conjunction with MACS, we developed a rapid oval cell isolation protocol. The sorted cells formed colony when cultured in vitro. Cells in the colony expressed albumin or CK19 or coexpressed both and BrdU incorporation test was positive. RT-PCR on colony showed expression of albumin and CK19 gene. CONCLUSION: Hepatic oval cells in the 2-AAF/PH model had the properties of hepatic stem/progenitor cells. Using MACS, we established a method to isolate oval cells. The sorted hepatic oval cells can form colony in vitro which expresses different combinations of phenotypic markers and genes from both hepatocytes and cholangiocyte lineage.

2-Acetylaminofluorene↗
PubMed2004

[Outcome and efficacy of laparoscopic splenectomy in treatment of idiopathic thrombocytopenic purpura].

OBJECTIVE: To investigate the safety and efficacy of laparoscopic splenectomy (LS) in treatment of idiopathic thrombocytopenic purpura (ITP). METHODS: Twenty-one patients with ITP underwent LS. The data of preoperative and postoperative platelet counts, intraoperative blood loss, recovery time, hospital stay time, and complications were analyzed prospectively. RESULTS: The platelet count was elevated rapidly in one week, and peristalsis of alimentary tract was recovered in 24 hours after operation in all cases. All patients got out of bed within 6 hours postoperatively. Their mean hospitalization time was 4 days. Complications were seen in 4 cases, of which one case underwent laparotomy, one case underwent laparoscopy once more to stop bleeding, one case developed subdiaphragmatic infection, and one case developed subcutaneous emphysema. Sixteen patients were followed up, and 2 patients relapsed. CONCLUSION: LS is a relatively safe and effective measure for treatment of ITP.

Adolescent↗