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Biomedical subjects

Yong Zeng

Publications and source records attributed to Yong Zeng.

At least 37 records · Page 2Linked to original sources
PubMed2006

Intramuscular hepatitis B immune globulin combined with lamivudine in prevention of hepatitis B recurrence after liver transplantation.

BACKGROUND: Combined hepatitis B immune globulin (HBIg) and lamivudine in prophylaxis of the recurrence of hepatitis B after liver transplantation has significantly improved the survival of HBsAg positive patients. This study was undertaken to evaluate the outcomes of liver transplantation for patients with hepatitis B virus (HBV). METHODS: A retrospective chart analysis and a review of the organ transplant database identified 51 patients (43 men and 8 women) transplanted for benign HBV-related cirrhotic diseases between June 2002 and December 2004 who had survived more than 3 months. HBIg was administered intravenously during the first week and intramuscularly thereafter. RESULTS: At a median follow-up of 14.1 months, the overall recurrence rate in the 51 patients was 3.9% (2/51). The overall patient survival was 88.3%, and 82.4% after 1 and 2 years, respectively. A daily oral dose of 100 mg lamivudine for 2 weeks before transplantation for 10 patients enabled 57.1% (4/7) and 62.5% (5/8) of HBV-DNA and HBeAg positive patients respectively to convert to be negative. Intramuscular HBIg was well tolerated in all patients. CONCLUSION: Lamivudine combined with intramuscular HBIg can effectively prevent allograft from the recurrence of HBV after liver transplantation.

Antiviral Agents↗
PubMed2006

Caudate lobectomy by the third porta hepatis anatomical method: a study of 16 cases.

BACKGROUND: The treatment for primary tumor in the caudate lobe of the liver is difficult because of its unique anatomical location. This study was undertaken to improve operative techniques and results by a new anatomical method of caudate lobectomy. METHODS: Clinical data of 16 patients who had had caudate lobectomy for the liver from January 1996 to November 2004 were retrospectively analyzed. The third porta hepatis anatomical method was performed in all 16 patients. Operative time, intraoperative blood loss, postoperative complications were recorded. The 1-, 3-, and 5-year survival rates of 13 patients with caudate lobe carcinoma were followed up. Anatomical status, operative routes, operative procedures, liver blood supply were evaluated. RESULTS: The operation was successful in the 16 patients. The operative time was 255+/-70 minutes and blood loss 740+/-402 ml. None of the patients died from massive bleeding during the operation, nor did complications such as biliary fistula and liver failure occurred. In 13 patients with malignant tumor, 7 died from recurrence and metastasis of the tumor and the other 6 are still alive at the end of follow-up. One patient has survived for 6 years. The 1-, 3-, and 5-year survival rates in the 13 patients were 83.9%, 58.7% and 39.2%, respectively. CONCLUSION: Caudate lobectomy by the third porta hepatis anatomical method can improve operative effect and increase the resection probability for solitary tumor in the caudate lobe.

Adult↗
PubMed2006

Prediction of the concentration of chlorophyll-a for Liuhai urban lakes in Beijing City.

The weekly water quality monitor data of Liuhai lakes between April 2003 and November 2004 in Beijing City were used as an example to build an artificial neural networks (ANN) model and a multi-varieties regression model respectively for predicting the fresh water algae bloom. The different predicted abilities of the two methods in Liuhai lakes were compared. A principle analysis method was first used to select the input variables of the models to avoid the phenomenon of collinearity in the data. The results showed that the input variables for the artificial neural networks were T, TP, transparency(SD), DO, chlorophyll-a (Chl-a), pH and the output variable was Chl-a. A three layer Levenberg-Marguardt feed forward learning algorithm in ANN was used to model the eutrophication process of Liuhai lakes. 20 nodes in hidden layer and 1 node of output for the ANN model had been optimized by trial and error method. A sensitivity analysis of the input variables was performed to evaluate their relative significance in determining the predicted values. The correlation coefficient between predicted value and observed value in all data and in test data were 0.717 and 0.816 respectively in the artificial neural networks. The stepwise regression method was used to simulate the linear relation between Chl-a and temperature, of which the correlation coefficient was 0.213. By comparing the results of the two models, it was found that neural network models were able to simulate non-linear behavior in the water eutrophication process of Liuhai lakes reasonably and could successfully estimate some extreme values from calibration and test data sets.

China↗
PubMed2006

[Using vein grafts in living donor liver transplantation].

OBJECTIVE: To study the use of vein grafts in adult-to-adult (AA) living donor liver transplantation (LDLT), we transplanted recipient vena saphena magna grafts for drainage of the paramedian portion of the right lobe liver grafts without a middle hepatic vein in LDLT. METHODS: From January 2002 to March 2006, 26 patients underwent A-A LDLT, and recipient saphenous vein grafts were used for revascularization of veins and arteries such as: tributaries of the middle hepatic vein from V5, V8; right inferior hepatic vein; injured portal vein; and hepatic artery. RESULTS: Total outflow reconstruction ratio of V5, V8 and right inferior hepatic vein was 76.9% (20/26), the ratio of one-vein reconstruction was 57.7%, and the ratio of two-vein reconstruction was 19.2%. Reconstruction patterns and cases were demonstrated as follows: V5 (n=3), V8 (n=2), V5 and V8 (n=3), V5 and right inferior hepatic vein (n=1), V8 and right inferior hepatic vein (n=1), right inferior hepatic vein (n=10), injured portal vein of the donor (n=1). Total ratio of hepatic artery bypass grafting was 11.5% (3/26), anastomosis between hepatic artery and abdominal aorta (n=2), and anastomosis between hepatic artery and hepatic artery (n=1). Doppler ultrasound showed no thrombosis and the blood flowed smoothly and without venous outflow obstruction during the 2 to 48 months follow-up period. CONCLUSION: Reconstruction of V5 or V8 outflow and hepatic artery bypass grafting using vena saphena magna of the recipients can provide sufficient venous outflow and prevent the small-for-size syndrome and solve hepatic artery complications. This approach can be recommended.

Adult↗
PubMed2006

[Big Y chromosome not significantly influences outcomes of in vitro fertilization and embryo transfer].

OBJECTIVE: To evaluate the influence of big Y chromosome on the outcomes of in vitro fertilization and embryo transfer. METHODS: Data of 127 cycles of IVF/ICSI-ET, performed in our Reproductive Medicine Center from March 2001 to June 2003 were analyzed. The patients were divided into two groups according to the length of chromosome: Group A, 56 cycles with big Y chromosome RESULTS: No significant difference was observed in the quality of embryos and in the and Group B, 71 cycles with normal karyotype. rates of fertilization, cleavage, clinical pregnancy, implantation, miscarriage, ectopic pregnancy, dead infant delivery, malformation, CONCLUSION: Big Y chromosome has no significant influence on the baby boy delivery and baby girl delivery between the two groups. development of embryos and the outcome of pregnancy.

Chromosomes, Human, Y↗
PubMed2005

Diagnosis and treatment of bacterial pneumonia in liver transplantation recipients: report of 33 cases.

BACKGROUND: Bacterial pneumonia in the recipients of liver transplantation (LTX) is a common postoperative complication influencing the prognosis greatly. In this article, the diagnosis and treatment of bacterial pneumonia in 33 LTX recipients are reported. METHODS: From February 1999 to January 2003, a total of 103 patients underwent allogeneic LTX at our center; afterwards, a retrospective analysis was made on their postoperative clinical manifestations, including symptoms (expectoration, panting and fever), sign (rale), results of laboratory examinations (white blood cell count and sputum culture of tracheal secretions or pleural fluid culture), and chest X-ray films. The following data of the pneumonia and non-pneumonia groups were collected, and the rank sum test (SPSS 11.0, Wilcoxon's method) was used to analyze the duration of postoperative respirator utilization and the volume of pleural effusion through pleurocentesis or pleural drainage. RESULTS: In the 103 patients, 33 experienced 53 episodes of bacterial pneumonia during their hospital stay after transplantation, 14 of them (42.42%) had more than three manifestations of the seven mentioned above. The pathogens causing bacterial pneumonia included Pseudomonas aeruginosa (17.48%), Klebsiella pneumoniae (15.53%), Acinetobacter baumannii (10.68%), and Staphylococcus aureus (7.77%). Amilkacin, tienam, ciprofloxacin, vancomycin, etc. were the antibiotics of choice against those bacteria. Acute rejection occurred during the treatment of bacterial pneumonia in 16 patients, and 5 of them died. Wilcoxon's rank sum test of the data indicated that the pneumonia group had longer duration of postoperative ventilator treatment and larger volume of pleural effusion than the non-pneumonia group (P < 0.05). CONCLUSIONS: The clinical manifestations of pneumonia after LTX might be atypical, and special attention should be paid to the respiratory symptoms and signs within 2 months after LTX. Whenever the diagnosis of bacterial pneumonia is confirmed, consideration should be given to reasonable use of antibiotics and regulation of immunity in addition to other routine therapies.

Adult↗
PubMed2005

Clear cell sarcoma of the kidney: up-regulation of neural markers with activation of the sonic hedgehog and Akt pathways.

PURPOSE AND EXPERIMENTAL DESIGN: Clear cell sarcoma of the kidney (CCSK), the second most common renal tumor in children, poses significant diagnostic challenges. No positive diagnostic markers are available, and the pathogenesis of CCSK remains an enigma. To address these challenges, the gene expression patterns of 14 CCSKs were compared with 15 Wilms tumors and 3 fetal kidney samples using oligonucleotide arrays. RESULTS: Using unsupervised methods, the gene expression profile of CCSK was distinctive: differentially expressed genes could largely be grouped into four categories: (a) a wide variety of neural markers, (b) members of the Sonic hedgehog pathway, (c) members of the phosphoinositide-3-kinase/Akt cell proliferation pathway, and (d) known therapeutic targets. Corresponding changes in critical proteins using Western blot and/or immunohistochemistry confirmed the up-regulation of these pathways and proteins. In particular, CD117 and epidermal growth factor receptor are up-regulated at the protein level in many CCSKs, providing potential therapeutic targets. One of the neural markers, nerve growth factor receptor, represents a promising diagnostic tool for CCSK. CONCLUSIONS: This study suggests that CCSKs arise within a renal mesenchymal cell that shows a wide variety of neural markers. As such, it seems to be susceptible to genetic changes also seen in a variety of other neuroectodermal and neuronal tumors, including activation of Sonic hedgehog and phosphoinositide-3-kinase/Akt pathways. Involvement of these pathways in CCSKs implicates their widening role in tumorigenesis.

Biomarkers, Tumor↗
PubMed2005

[An experimental study of mucociliary clearance of trachea reconstructed with free jejunum].

OBJECTIVE: To investigate tracheal mucociliary transport change after reconstructed with free jejunum. METHODS: Twelve canine models of extensive circumferential tracheal defects reconstructed with revascularized jejuno combined with Ni-Ti alloy mesh tube were established. Every canine model was marked in cervical skin projecting the lower resected margin of trachea lumen and was injected 50% barium sulfate mucilage as a tracer into the trachea lumen under bronchoscopy. Record the time from tracer injected into trachea lumen to its arriving glottis (mucociliary transit time, MTT) and the length from tracer injected into trachea lumen to glottis (mucociliary transport length, MTL). Mucociliary transit rate (MTR), as MTL/ MTT, was calculated. The same procedure was performed at preoperative and postoperative 7th day, 1 month, 3 months and 6 months. RESULTS: There were statistical significance between preoperative MTR and 1 month postoperative MTR (P < 0.05). There were no differences between preoperative MTR and postoperative MTR at the 7th day, 1 month, 3 months and 6 months. There were also no differences between postoperative MTR at the 7th day and 1 month, 3 months and 6 months. CONCLUSION: In new tracheal tract reconstructed with free jejunum, MTR becomes normal at 3 months postoperatively.

Animals↗
PubMed2005

Liver transplantation for patients with hepatolithiasis.

BACKGROUND: Because of its complicated pathological features such as repeated cholangitis and multiple operations, hepatolithiasis is difficult to treat and often lead to portal hypertension, and liver failure. The aim of this study was to investigate the indications of orthotopic liver transplantation (OLT)for patients with hepatolithiasis and the improvement of operative techniques and the treatment of postoperative complications. METHODS: The data of 4 patients with hepatolithiasis who had undergone OLT at our department in recent years were reviewed retrospectively. RESULTS: The 4 patients with hepatolithiasis complicated with secondary biliary cirrhosis in end-stage liver disease included 1 woman and 3 men. One patient underwent OLT using veno-venous bypass prior to the mobilization of the liver. Two patients were subjected to liver transplantation with improved piggyback technique without bypass. One patient received OLT without bypass. All patients were operated on successfully and recovered uneventfully. Patient 1 had bleeding from the digestive tract on the postoperative day 6. Patient 2 had hemorrhage from the digestive tract and a leakage of end-to-side intestinal anastomosis on the postoperative day 44. Patient 4 was reoperated on because of hemorrhage from the anastomotic stoma of the hepatic artery on the postoperative days 8 and 10. In the 4 patients the mean operative time was 7.9 hours and blood loss was 910 ml. Postoperative pathological analysis revealed biliary liver cirrhosis. Follow-up of all patients showed good conditions. CONCLUSIONS: Hepatolithiasis with secondary biliary liver cirrhosis in patients with end-stage liver disease is indicated for liver transplantation. Veno-venous bypass prior to the mobilization of the liver and improved piggyback technique can lower the incidence of intraoperative bleeding, the duration of surgery and postoperative complications.

Adult↗
PubMed2004

Modified spontaneous emission from a two-dimensional photonic crystal.

Decay kinetic properties of a two-level atom near the band edges of a two-dimensional photonic crystal are studied based on the Green's function expression for the evolution operator. Our calculations show that the decay kinetics can be controlled by changing the atomic parameters. We also find that there is a quite wide lifetime distribution in the spontaneous emission process.

Journal Article↗
PubMed2004

Light damage induced changes in mouse retinal gene expression.

Oxidative stress plays a role in the light damage model of retinal degeneration as well as in age-related macular degeneration. The purpose of this study is to identify retinal genes induced by acute photo-oxidative stress, which may function as mediators of apoptosis or as survival factors. To accomplish this, Balb/c mice were exposed to bright cool white fluorescent light for 7 hr. Retinas were then isolated for total RNA preparation followed by Affymetrix DNA microarray analysis to compare gene expression in light damaged mice to unexposed controls. Three independent light damage experiments were carried out and statistical filters were applied to detect genes with expression changes averaging at least two-fold. Quantitative PCR was carried out to confirm altered gene expression. Seventy genes were upregulated at least two-fold immediately following light damage. QPCR confirmed upregulation of all 10 genes tested. The upregulated genes fall into several categories including antioxidants: ceruloplasmin, metallothionein, and heme oxygenase; antiapoptotic gene: bag3, chloride channels: clic1 and clic4; transcription factors: c-fos, fra1, junB, stat1, krox-24 and c/ebp; secreted signaling molecules: chitinase 3-like protein 1 and osteopontin; inflammation related genes: MCP-1 and ICAM1 and others. Upregulation of five interferon-gamma responsive genes suggests elevated interferon levels after light damage. Upregulation of three components of the AP-1 transcription factor is consistent with previous evidence implicating AP-1 in light damage pathogenesis. Four copper or iron binding proteins were upregulated, suggesting that photo-oxidative stress may affect metal homeostasis. The genes found upregulated by light damage may affect the survival of photoreceptors subjected to photo-oxidative stress.

Animals↗
PubMed2004

Allelic variation of serotonin transporter function modulates the brain electrical response for error processing.

A functional length variation in the transcriptional control region of the serotonin transporter gene (5-HTTLPR) influences brain function, personality traits, and susceptibility to psychiatric disorders. Here we measured prefrontal brain function by means of event-related potentials during an error processing paradigm. Physiologically, occurrence of an error elicits two specific electrical responses in the prefrontal cortex, the early error related negativity (Ne/ERN) and the later occurring error positivity (Pe), reflecting different components of error processing. Healthy subjects with one or two copies of the low-activity 5-HTTLPR short variant showed significantly higher amplitudes of the Ne/ERN and a trend to higher amplitudes of the Pe as compared to age- and gender-matched individuals homozygous for the long allele. Performance measures and latencies of these ERP-components did not differ between groups. These results indicate that the 5-HTTLPR short variant is associated with enhanced responsiveness of the brain and further supports the notion that prefrontal brain function is influenced by allelic variation in serotonin transporter function.

Adult↗
PubMed2004

A retinal neuronal developmental wave of retinoschisin expression begins in ganglion cells during layer formation.

PURPOSE: Mutations in the retinoschisin gene, RS-1, cause juvenile X-linked retinoschisis (XLRS), a dystrophy characterized by delamination of the inner retinal layers, leading to visual impairment. Although the retinoschisin protein (RS) is expressed most abundantly in photoreceptors in the outer retina, XLRS disease affects the innermost retinal layers, including the nerve fiber layer that contains retinal ganglion cells (RGCs). Considering the histopathological and electrophysiological characteristics of the clinical disease, the present study was conducted to evaluate the local cellular expression of RS-1 during retinal development. METHODS: RS protein and RS-1 mRNA were localized to specific retinal cell types in embryonic to adult mice by immunohistochemistry, confocal immunofluorescence microscopy, catalyzed reporter deposition in situ hybridization, and laser capture microdissection/RT-PCR. RESULTS: RS-1 mRNA was expressed first in RGCs by postnatal day (P)1, after terminal differentiation. Expression then moved posteriorly through the retina in a spatial and temporal developmental wave, as additional neuronal classes were born and synaptic layers were formed. RS was expressed by bipolar cells at a time when these neurons were establishing functional synapses with photoreceptors, evidenced by the appearance of the electroretinogram b-wave between P12 and P14. CONCLUSIONS: All major classes of adult retinal neurons, with the possible exception of horizontal cells, express RS protein and mRNA, strongly suggesting that retinoschisin in the inner retina is synthesized locally rather than being transported, as earlier proposed, from distal retinal photoreceptors. Continued expression of RS by mature inner-retinal neurons supports the possibility of a therapeutic strategy of protein replacement to treat both infants and adults with XLRS.

Aging↗
PubMed2004

RS-1 Gene Delivery to an Adult Rs1h Knockout Mouse Model Restores ERG b-Wave with Reversal of the Electronegative Waveform of X-Linked Retinoschisis.

PURPOSE: To create and evaluate a mouse model of human X-linked juvenile retinoschisis (XLRS) and then investigate whether supplementing with the retinoschisin protein by gene delivery can reverse the abnormal "electronegative" electroretinogram (ERG) retinal response. METHODS: An X-linked retinoschisis mouse (Rs1h-KO) model was created by substituting a neomycin resistance cassette for exon 1 and 1.6 kb of intron 1 of Rs1h, the murine orthologue of the human RS-1 gene. RS protein was evaluated by immunohistochemistry and Western blot analysis with a polyclonal RS N-terminus antibody. Retinal function was evaluated by conventional, full-field flash ERG recordings. RS protein supplementation therapy was evaluated by gene transfer with an AAV(2/2)-CMV-Rs1h vector containing C57BL/6J Rs1h cDNA under the regulation of a CMV promoter, and ERG functional analysis was performed. RESULTS: No RS protein was detected by Western blot analysis or immunohistochemistry in the Rs1h-KO mouse. Dark-adapted ERG responses showed an electronegative configuration, with b-wave reduction in both Rs1h(-/Y) and Rs1h-/- mice, typical of XLRS in humans. Histologic examination of Rs1h-KO mice showed disorganization of multiple retinal layers, including duplication and mislocalization of ganglion cells, laminar dissection through the inner plexiform layer, disorganization of the outer plexiform layer, loss of regularity of the outer nuclear layer, and shortening of the inner/outer segments with mislocalization of photoreceptor nuclei into this layer. After intraocular administration of AAV(2/2)-CMV-Rs1h, immunohistochemistry showed retinoschisin expression in all retinal layers of Rs1h(-/Y) mice, and ERG recordings showed reversal of the electronegative waveform and restoration of the normal positive b-wave. CONCLUSIONS: The RS-KO mouse mimics structural features of human X-linked juvenile retinoschisis with dissection through, and disorganization of, multiple retinal layers. The Rs1h-KO functional deficit results in an electronegative ERG waveform that is characteristic of human retinoschisis disease and that implicates a synaptic transmission deficit in the absence of retinoschisin protein. Replacement therapy by supplementing normal Rs1h protein in the adult Rs1h-KO mouse restored the normal ERG configuration. This indicates that gene therapy is a viable strategy of therapeutic intervention even in the postdevelopmental adult stage of XLRS disease.

Animals↗
PubMed2004

Liver transplantation for patients with hepatic alveolar echinococcosis in late stage.

BACKGROUND: Failed surgical treatment and multiple operations often lead to liver failure and make it difficult to be treated by traditional methods. Liver transplantation may be the ideal and the last choice. In this study we tried to explore the indication of liver transplantation for hepatic alveolar echinococcosis (HAE) and the improvement of intraoperative treatment. METHODS: Five patients who had received liver transplantation of hepatic alveolar echinococcosis in our hospital from 1999 through 2003 were analyzed retrospectively. RESULTS: All the patients (3 were male and 2 female) were in late stage of hepatic alveolar echinococcosis. During orthotopic liver transplantation(OLT), 4 patients underwent veno-venous bypass, 3 were subjected to veno-venous bypass prior to the mobilization of the liver, and 2 received placement of T tube in the bile duct. In all the patients treated successfully by OLT, 4 recovered, and 1 died of severe infection and acute rejection after operation. T tube fell off in one patient. Postoperatively, pathological diagnosis verified hepatic alveolar echinococcosis. Four patients were followed up to the present, showing a good life quality and work capacity. CONCLUSIONS: Hepatic alveolar echinococcosis in late stage can be considered as one of the indications of liver transplantation. Technique of veno-venous bypass prior to the mobilization of the liver could decrease operative time and bleeding. Early diagnosis and treatment of the disease ensures a better prognosis.

Adolescent↗
PubMed2003

Anxiety-related traits in mice with modified genes of the serotonergic pathway.

The neurobiology of anxiety is complex, reflecting the cumulative physiological effects of multiple genes. These genes are interactive with each other and with the environment in which they are expressed. Variation in genes coding for proteins that control serotonin (5-HT) system development and plasticity, establish 5-HT neuron identity, and modulate 5-HT receptor-mediated signal transduction and cellular pathways have been implicated in the genetics of anxiety and related disorders. Here, we selected anxiety and avoidance as paradigmatic traits and behavior and cover both traditional studies with inbred murine strains and selected lines which have been modified by gene knockout technologies. The design of a mouse model partially or completely lacking a gene of interest during all stages of development (constitutive knockout) or in a spatio-temporal context (conditional knockout) is among the prime strategies directed at elucidating the role of genetic factors in fear and anxiety. In many cases, knockout mice have been able to confirm what has already been anticipated based on pharmacological studies. In other instances, knockout studies have changed views of the relevance of 5-HT homeostasis in brain development and plasticity as well as processes underlying emotional behavior. In this review, we discuss the pertinent literature regarding phenotypic changes in mice bearing inactivation mutations of 5-HT receptors, 5-HT transporter, monoamine oxidase A and other components of the serotonergic pathway. Finally, we attempt to identify future directions of genetic manipulation in animal models to advance our understanding of brain dysregulation characteristic of anxiety disorders.

Animals↗
PubMed2003

Gene therapy for choroideremia: in vitro rescue mediated by recombinant adenovirus.

Choroideremia (CHM) is an X-linked retinal degenerative disease resulting from a lack of functional Rab Escort Protein-1 (REP-1). As a first step in developing gene-based therapies for this disease, we evaluated the feasibility of delivering functional REP-1 to defective lymphocytes and fibroblasts isolated from individuals with CHM. A recombinant adenovirus delivering the full-length human cDNA encoding REP-1 under the control of a cytomegalovirus promoter was generated. Adenovirus-mediated delivery of REP-1 rescued the defective cells as assessed through protein and enzymatic assays. Ultimately, it may be possible to use virus-mediated delivery of REP-1 to evaluate disease intervention in vivo.

Adaptor Proteins, Signal Transducing↗