Biomedical subjects

Yong Chen

Publications and source records attributed to Yong Chen.

At least 217 records · Page 12Linked to original sources

PubMed2003

[Clinical evaluation of laparoscopic radical hysterectomy with pelvic and para-aortic lymphadenectomy in patients with cervical cancer].

OBJECTIVE: To evaluate the effective, results and complications in patients with cervical cancer who consented to undergo laparoscopic radical hysterectomy and retroperitoneal lymphadenectomy. METHODS: In 57 consecutive patients with stage Ia to IIb cervical cancer, laparoscopic radical hysterectomy and lymphadenectomy were performed. Forty-eight patients had squamous cell carcinomas, 7 patients had adenocarcinomas, and 2 patients had adenosquamous carcinomas of the cervix. RESULTS: All but 2 surgical procedures were completed laparoscopically. The average operative time was 186 min (150 - 320 min). The average blood loss was 168 ml (120 - 700 ml). Average numbers of pelvic and paraaortic lymph nodes removed were 18.6 (12 - 23) and 8.2 (6 - 12), respectively. Eight patients (14.0%) had positive lymph nodes. All surgical margins were macroscopically negative. Operative cystotomies occurred in 2 patients and one patient with venous injuries were repaired laparoscopically. Two other patients underwent laparotomy to control bleeding or repair ascending colon. After surgery, patients passed gas in 2.3 days and self-voided in 10.2 days on average. Follow-up has been provided every 3 months. There have been 3 cases of recurrences, one patient uncontrolled, and one patient ureteral constriction. Three patients have retention of urine. CONCLUSIONS: Laparoscopic radical hysterectomy and lymphadenectomy can be successfully completed in patients with cervical cancer with acceptable operation complications, a less injury and recovery time, and may become preferred for treating early cervical cancer.

Adult↗

PubMed2003

[Intravascular administration of pingyangmycin lipiodol emulsion for Klippel-Trenaunay syndrome: clinical analysis of 7 cases].

OBJECTIVE: To define the arteriographic features of Klippel-Trenaunay sydrome (KTS) and explore the feasibility of the treatment with intravascular administration of pingyangmycin lipiodol emulsion (PLE). METHODS: Seven patients with KTS underwent arteriography followed by therapy with PLE administration (containing pingyangmycin 8-16 mg and lipiodol 4-6 ml) into the trunk of the arteries of all impaired extremities. The therapeutic effect and postoperative complications were observed. RESULTS: Arteriography revealed abundant small branches of the runoff arteries, showing sinusoid changes of varied sizes in 5 cases by staining of the soft tissue. During the 3 to 30-month follow-up, swelling of the extremities was obviously improved in 5 cases after PLE therapy, which failed to produce obvious effect in 1 case and recurrence was detected in another. The major complications included paresthesia of the limbs, serum transaminase disorder and local skin necrosis. CONCLUSION: Arteriography can detect the lesions of the arteries and soft tissues in the affected extremity of patients with KTS, intravascular administration of PLE was effective to alleviate the hypertrophy of the limbs.

Adolescent↗

PubMed2003

[Changes of serum IL-1, IL-2R and TNF-alpha levels in divers after 150 m Heliox saturation -182 m excursion in the open sea diving].

OBJECTIVE: To observe the change of the serum IL-1, IL-2R and TNF-alpha levels in divers after deep saturation in the open sea diving. METHOD: Eight divers experienced 150 in Heliox saturation -182 in excursion diving. Serum levels of IL-1, IL-2R and TNF-alpha level before and after diving were measured by ELISA. RESULTS: There was no significant change of serum TNF-alpha level after saturation diving, but serum levels of IL-1, IL-2R increased significantly after saturation diving. CONCLUSION: Deep open sea saturation diving had significant effects on serum IL-6, IL-2R levels of the divers.

Adult↗

PubMed2003

Argon supper-cryosurgery for patients with middle and late stage liver cancer.

OBJECTIVE: To assess the value of argon supper-cryosurgery for 42 patients with middle and late stage liver cancer. METHODS: Forty-two patients who had received argon supper-cryosurgery were analyzed retrospectively in terms of their clinical characteristics as well as the performance of argon supper-cryosurgery. RESULTS: All patients were ameliorated in symptoms shortly after the operation, including pain alleviation, psyche straightening up, alpha-fetoprotein descending or recovery. Jaundice occurred in 1 patient and intraabdominal hemorrhage in 2. The levels of aspartate transaminase and alanine transaminase in all patients were elevated 1 month after the operation, and normalized after protective therapy of the liver. No operative death was noted. CONCLUSIONS: Cold and heat reversed therapy of argon supper-cryosurgery can drastically destroy tumor tissue, especially the tumors which are too large to resect or close to the large vessels. It is applicable to increase the operative rate, decrease the operative death rate, and enlarge the therapeutic scope.

Adult↗

PubMed2003

Cloning and expression of cDNAs from hepatitis E virus structural gene.

OBJECTIVE: To obtain recombinant antigen for development of anti-HEV ELISA kit and vaccine against hepatitis E virus infection. METHODS: A 492 base cDNA was collected from 5-terminus of open reading frame 2 (ORF2) among epidemic hepatitis E virus (HEV) isolated from Xinjiang, Western China. The fragment was digested with BamH I and EcoR I, and inserted into vector pGEX-4T-3 which was also digested by the same enzyme. The recombinant plasmid was transformed into E.coli TG-1 and the fusion protein expressed was confirmed by Western blot analysis using serum of a patient with hepatitis E. RESULTS: The recombinant plasmid was identified and confirmed with enzyme digestion, polymerase chain reaction (PCR) and sequencing, respectively. A protein band of about 46 kDa was demonstrated by SDS-PAGE and designated GST-pORF2. The result of Western blot analysis suggested that the fusion protein reacted with anti-HEV positive sera at a dilution of 1:100. CONCLUSION: The recombinant protein GST-pORF2 may be useful in developing anti-HEV ELISA kit and vaccine against hepatitis E virus infection.

Animals↗

PubMed2003

A rat model for acute hepatic failure.

OBJECTIVE: To develop a surgical model of acute hepatic failure. METHODS: Hepatectomy was performed in rats according to the method described by Higgins and Anderson. Ninety percent liver resection (removing the left lateral, median, and right lateral lobes) (n=7) and 95% liver resection leaving only half of the caudate lobe (n=13) were performed. Hypoglycemia was corrected by giving 20% glucose in the drinking water, coupled with repeated intraperitoneal injection of 5% glucose adapted to glycemia. While the survival rate, alanine transaminase (ALT) and bilirubin were observed. RESULTS: 95% liver resection decreased survival rates of the rats from 86% (90% liver resection) to 23% (P<0.05), and increased bilirubin levels (4.04+/-2.84 mg/dL vs. 1.25+/-1.85 mg/dL [90% liver resection]). CONCLUSION: 95% liver resection is a good rat model for acute hepatic failure.

Alanine Transaminase↗

PubMed2003

Percutaneous transhepatic metal versus plastic biliary stent in treating malignant biliary obstruction: a multiple center investigation.

OBJECTIVE: To compare the efficacy of metal versus plastic biliary stent implantation in the treatment of malignant biliary obstruction. METHODS: Percutaneous transhepatic self-expandable metal stent (MS, n=61) and 10F plastic stent (PS, n=34) were placed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival of the patients and the rates of stent patency. RESULTS: The 30-day mortality rate was lower in the MS group (6/61, 9.8%) than in the PS group (9/34, 26.5%, P<0.05). The 30-day reobstruction rate and the complication rate were 15.0%, 16.4% in the MS group and 32.4%, 29.4% in the PS group, respectively (P<0.01). The median patency period of stents and median survival period of the patients were 230 days, 224 days in the MS group and 90 days, 94 days in the PS group, respectively (P<0.01). CONCLUSION: Metal stent is clinically superior to plastic stent in the treatment of malignant biliary obstruction.

Adult↗

PubMed2003

[Comparative assessment of clinical efficacy of percutaneous transhepatic metal versus plastic biliary stent implantation for malignant biliary obstruction: a multi-centered investigation].

OBJECTIVE: To compare the clinical efficacy of metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction. METHODS: Percutaneous transhepatic implantations of self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) were performed in 95 patients with malignant biliary obstruction selected from 3 hospitals of Guangdong Province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the patients' survival and stent patency rates. RESULTS: The 30-day mortality rate was lower in MS group (6/61, 9.8%) than in PS group (9/34, 26.5%, P<0.05). The 30-day reobstruction rate and incidence of complications were 15.0%, 16.4% in MS group and 32.4%, 29.4% in PS group, respectively (P<0.01). The median patency period of the stents and median survival period of the patients were 230 d, 224 d in MS group and 90 d, 94 d in PS group, respectively (P<0.01). CONCLUSION: Metal stent implantation is superior to plastic stent for treatment of malignant biliary obstruction.

Adult↗

PubMed2003

[Interventional radiologic therapy for arteriovenous malformations in the face].

OBJECTIVE: To introduce the technique of transarterial interventional embolization treating for arteriovenous malformations (AVM) in the face. METHODS: From April 1998, 17 patients have been treated with this method. Seldinger's maneuver was used in this series. Of them, 11 cases received only interventional embolization; 6 cases received both interventional embolization and surgical resection. RESULTS: The interventional embolization was effective in all the 17 cases, which was confirmed by immediate angiography. Their clinical symptoms were gradually relieved. Interventional embolization obviously decreased hemorrhage during surgical resection. CONCLUSIONS: Interventional embolization provides a new way for the treatment of AVM. Preoperative embolization can lower the surgical risk as it obviously decreases hemorrhage during the surgical procedure.

Adolescent↗

PubMed2003

[Purification by FPLC and characterization of Mycobacterium tuberculosis heat-resistant peptide antigen stimulating proliferation of human gammadelta+ T cells].

AIM: To purify Mycobacterium tuberculosis heat-resistant peptide antigen(Mtb-Ag) that can stimulate gammadelta+ T cells. METHODS: Mtb-Ag was first separated by fast performance liquid chromatography (FPLC) with S-100 column, and then the components including low molecular weight peptide antigens (Mtb-LW-Ag) peaks were purified by FPLC with Mono Q column. Activity of the purified Mtb-LW-Ag that stimulates human gammadelta+ T cell proliferation was examined by flow cytometry. RESULTS: Mtb-Ag was separated into four peaks(A, B, C and D) by FPLC S-100 column and the peak B, C and D contained Mtb-LW-Ag. The peak B was further separated into six main peaks(B-I-VI), peak C only one main peak(C-main), and peak D eight main peaks(D-I-VIII) by FPLC Mono Q column. Furthermore, peak B, C, B-III and C-main peptide could significantly stimulate human gammadelta+ T cell proliferation in a dose of 0.1 mg/L. CONCLUSION: Varied Mtb-LW-Ag peptides are purified from Mtb-Ag by FPLC, and the B-III and C-main peptides may be the main components of stimulating human gammadelta+ T cell proliferation.

Antigens, Bacterial↗

PubMed2003

[Characterization of Mycobacterium tuberculosis polypeptide antigen capable of stimulating the proliferation of human gammadeltaT cells].

AIM: To analyse biological properties of Mycobacterium tuberculosis polypeptide antigen(Mtb-Ag) that could stimulate the proliferation of human gammadeltaT cells. METHODS: Mtb secretory proteins and Mtb-Ag treated via dialysis or with pronase were used to stimulate human PBMCs. After being cultured for 10 days, the phenotype of responsive cells was analysed by flow cytometry. RESULTS: The proliferation stimulating activity to human gammadeltaT cells of dialysed Mtb-Ag did not decrease remarkably, whereas that of the pronase-treated Mtb-Ag reduced significantly. Moreover, the proliferative stimulating activity to gammadeltaT cells of Mtb-Ag was notably higher than Mtb secretory protein. CONCLUSION: The component in Mtb-Ag that can stimulate the proliferation of human gammadeltaT cells is a non-secretory and protase-sensitive polypeptides with M(r) over 10 000.

Antigens, Bacterial↗

PubMed2003

[Analysis of RAPD fingerprinting in Exserohilum monoceras strains].

Exserohilium monoseras is a potential agent for barnyardgrass (Echinochlao crus-galli) control. This study was to evaluate the genetic diversity of this fungus with 17 strains isolated from different rice growing regions of China by the random amplified polymorphic DNA (RAPD). Among 25 arbitrary primers, 20 primers could get enough amplified bands for all the strains. A total 239 products were amplified. Polymorphic bands were 95.8% of the total products. The 17 strains could be identified based on RAPD fingerprinting established in this study. Genetic distance calculation and cluster analysis resulted in great genetic variation among the strains. The genetic similarity was related with the morphology and the pathogenicity of the strains. The results showed that RAPD maker could be applied in the utilization and the identification of weed pathogen resources.

Ascomycota↗

PubMed2002

Neuregulin expression after focal stroke in the rat.

Upregulation of neuregulin has been demonstrated in traumatic brain injury, but a role for neuregulin in ischemic brain injury has not been investigated. Therefore, we used a rat permanent middle cerebral artery occlusion model to examine the distribution of neuregulin after the onset of ischemic stroke. We found an increase in immunohistochemical staining for neuregulin in the penumbral regions of the cortex. The increase in neuregulin appeared to be neuronal. There was no neuregulin co-localization with astrocytes or macrophages. These results demonstrate that neuregulin is induced in neurons following ischemic stroke and may be involved in neuroprotection and repair.

Animals↗

PubMed2002

Human growth hormone-regulated HOXA1 is a human mammary epithelial oncogene.

Increased mammary epithelial expression of the human growth hormone (hGH) gene is associated with the acquisition of pathological proliferation. We report here that autocrine hGH production by human mammary carcinoma cells increased the expression and transcriptional activity of the homeobox domain containing protein HOXA1. Forced expression of HOXA1 in human mammary carcinoma cells resulted in increased total cell number primarily by the promotion of cell survival mediated by the transcriptional up-regulation of Bcl-2. HOXA1 also abrogated the apoptotic response of mammary carcinoma cells to doxorubicin. Forced expression of HOXA1 in mammary carcinoma cells, in a Bcl-2-dependent manner, resulted in dramatic enhancement of anchorage-independent proliferation and colony formation in soft agar. Finally, forced expression of HOXA1 was sufficient to result in the oncogenic transformation of immortalized human mammary epithelial cells with aggressive in vivo tumor formation. Herein, we have therefore provided a molecular mechanism by which autocrine hGH stimulation of human mammary epithelial cells may result in oncogenic transformation.

Animals↗

PubMed2002

Similar electrophysiological changes in axotomized and neighboring intact dorsal root ganglion neurons.

We investigated electrophysiological changes in chronically axotomized and neighboring intact dorsal root ganglion (DRG) neurons in rats after either a peripheral axotomy consisting of an L5 spinal nerve ligation (SNL) or a central axotomy produced by an L5 partial rhizotomy (PR). SNL produced lasting hyperalgesia to punctate indentation and tactile allodynia to innocuous stroking of the foot ipsilateral to the injury. PR produced ipsilateral hyperalgesia without allodynia with recovery by day 10. Intracellular recordings were obtained in vivo from the cell bodies (somata) of axotomized and intact DRG neurons, some with functionally identified peripheral receptive fields. PR produced only minor electrophysiological changes in both axotomized and intact somata in L5 DRG. In contrast, extensive changes were observed after SNL in large- and medium-sized, but not small-sized, somata of intact (L4) as well as axotomized (L5) DRG neurons. These changes included (in relation to sham values) higher input resistance, lower current and voltage thresholds, and action potentials with longer durations and slower rising and falling rates. The incidence of spontaneous activity, recorded extracellularly from dorsal root fibers in vitro, was significantly higher (in relation to sham) after SNL but not after PR, and occurred in myelinated but not unmyelinated fibers from both L4 (9.1%) and L5 (16.7%) DRGs. We hypothesize that the changes in the electrophysiological properties of axotomized and intact DRG neurons after SNL are produced by a mechanism associated with Wallerian degeneration and that the hyperexcitability of intact neurons may contribute to SNL-induced hyperalgesia and allodynia.

Acute Disease↗

PubMed2002

Effects of nociceptin (13-17) in pain modulation at supraspinal level in mice.

This work was designed to observe the effects of nociceptin(13-17), one of the main metabolites of nociceptin (also termed orphanin FQ), in pain modulation at supraspinal level in mice. Intracerebroventricular (i.c.v.) administration of nociceptin/orphanin FQ(13-17) (N/OFQ(13-17)) (5, 0.5, 0.05, 0.005 nmol/mouse) dose-dependently induced potent hyperalgesic effects in the 48 degrees C warm-water tail-flick test in mice. I.c.v. pretreatment with N/OFQ(13-17) (5, 0.5, 0.05 nmol/mouse) potentiated the analgesic effects induced by morphine (i.p., 2 mg/kg) and reversed the hyperalgesic effects induced by N/OFQ (i.c.v., 5 nmol/mouse). The hyperalgesic effects induced by N/OFQ(13-17) could not be antagonized by [Nphe((1))]N/OFQ(1-13)NH((2)) or naloxone. These findings suggest that N/OFQ(13-17) may play important roles in pain modulation at supraspinal level in mice and elicits these effects through a novel mechanism independent of the N/OFQ receptor and the mu, delta and kappa opioid receptors.

Analgesia↗

PubMed2002

[Genetic basis of essential hypertension in Tibetan].

OBJECTIVE: To explore the role genetic factor plays in the pathogenes is of essential hypertension (EH) among Tibetans and to investigate whether angiotensinogen (AGT) is involved in the pathogenesis of EH. METHODS: A case-control association study was conducted among 353 essential hypertensive subjects and 317 genealogic structure-matched normotensive controls, all of Tibetan nationality. The correlation between polymorphism of M235T and 6A-->G variant in AGT gene and EH susceptibility in Tibetans was examined by polymerase chain reaction ( PCR) and PCR/RFLP (restriction fragment lengths polymorphism) with AspI and BstN I,respectively. RESULTS: (1) The affection rate of EH among the first-degree relatives of Tibetan EH proband was 43.3%. The heritability of EH was 77.2% +/- 13.3% by Falconer method. (2) The plasma rennin activity and angiotensin II (AngII) level among the EH patients were (1.95 +/- 0.11) microgram .L(-1).h(-1) and (72.6 +/- 4.6) ng/L, all significantly higher than those in the controls [(1. 59 +/- 0.11) microgram .L(-1).h(-1) and (51.7 +/- 4.6) ng/L, all P < 0.05].(3) The -6G allele frequency in the promoter of AGT gene was higher in EH group than in the control group (0.36 vs 0.27, kappa(2) = 9.35, P < 0.01). There was a weak association between -6A -->G variant and the plasma AngII level, and there was no significant difference in the genotype distribution and allele frequency of M235T variant between the hypertensive and normotensive groups (P > 0.05). CONCLUSION: Genetic factor plays an important role in the pathogenesis of essential hypertension and angiotensinogen gene might be one of the most key susceptibility genes for essential hypertension in Tibetan.

Adult↗

PubMed2002

Probing domain swapping for the neuronal SNARE complex with electron paramagnetic resonance.

Highly conserved soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins control membrane fusion at synapses. The target plasma membrane-associated SNARE proteins and the vesicle-associated SNARE protein assemble into a parallel four-helix bundle. Using a novel EPR approach, it is found that the SNARE four-helix bundles are interconnected via domain swapping that is achieved by substituting one of the two SNAP-25 helices with the identical helix from the second four-helical bundle. Domain swapping is likely to play a role in the multimerization of the SNARE complex that is required for successful membrane fusion. The new EPR application employed here should be useful to study other polymerizing proteins.

Cyclic N-Oxides↗