Biomedical subjects

Y Wu

Publications and source records attributed to Y Wu.

At least 685 records · Page 38Linked to original sources

PubMed1998

[Construction of retrovirus vector of bcr/abl mRNA cleaving ribozyme gene and its effects on K562 cells].

OBJECTIVE: To investigate the effect of bcr/abl fusion gene on the growth of chronic myeloid leukemia(CML) cells and to explore the feasibility of ribozyme in CML gene therapy. METHODS: A hammerhead ribozyme DNA targeting the bcr/abl (b3a2) transcript was synthesized, and recombinated into retroviral vector pLXSN forming pLRZXSN recon. By lipofectin mediated DNA transfection technique, pLRZXSN was introduced into K562 cells. The effects of the ribozyme on the growth of K562 cells and apoptosis were studied by leukemic colony assay, flow cytometry (FCM), reverse transcript-polymerase chain reaction (RT-PCR), detection of DNA fragmentation and electron microscope. RESULTS: 1. The number of K562 cell colony was inhibited by 85% after the cells were transfected for 48 hours. 2. The expression of bcr/abl mRNA and the fusion protein P210 was decreased sharply in K562 cells transfected with pLRZXSN for 48 and 72 hours, respectively. 3. The characteristics of apoptosis was revealed in K562 cells transfected with pLRZXSN, i.e. sub-G1 peak, DNA fragmentation and morphological changes. CONCLUSION: The ribozyme was capable of inhibiting the proliferation of K562 cells and inducing the cell apoptosis.

Apoptosis↗

PubMed1998

[Reconstruction of transcriptional regulatory elements of human alpha-fetoprotein gene].

OBJECTIVE: To construct vectors that express therapeutic genes specifically in hepatocellular carcinoma, the TREs (Tissue-specific transcriptional regulatory elements) of natural human alpha-fetoprotein (AFP) was reconstructed. METHODS: Using subcloning techniques, the -870 bp(-)-3.06 kb fragment of the natural human AFP TREs was deleted to construct an artificial AFP(e/p) TREs which contains the "core" promoter and the -3.06 kb(-)-5.1 kb fragment of natural human AFP TREs that contains enhancer activity. RESULTS: By using chloramphenicol acetyltransferase (CAT) assay, the artificial AFP(e/p) TREs showed an activity 1.8 fold as high as that of the natural AFP TREs in an AFP positive human hepatocarcinoma cell line HepG2, and it also remained to be tissue-specific since there was no activity was detected in an AFP negative human larynxcarcinoma cell line Hep2. CONCLUSIONS: These results indicate that the artificial AFP(e/p) TREs we have constructed has higher activity than the natural AFP TREs and it also remains its hepatocarcinoma specificity. The reconstructed AFP(e/p) TREs is suitable for constructing of gene therapy vector with hepatocarcinoma expression specificity.

Carcinoma, Hepatocellular↗

PubMed1998

[Clinical study on improving effect of Buyang Huanwu decoction on plasma thromboxane B2, 6-keto-prostaglandin F1 alpha, endothelin and calcitonin gene related peptide in primary nephrotic syndrome patients].

OBJECTIVE: To explore the mechanism of Buyang Huanwu Decoction (BHD) in treating primary nephrotic syndrome (PNS). METHODS: Based on the treatment of prednisone acetate and cytoxan, two groups of PNS patients were treated with aspirin and persantin (western medicine group, 35 patients) and BHD and western medicine (TCM-WM group, 35 patients) respectively. The effect on anticoagulation was observed and compared. Plasma levels of thromboxane B2 (TXB2), 6-keto-prostaglandin F1 alpha (6-Keto-PGF1 alpha), endothelin (ET), calcitonin gene related peptide (CGRP) were determined before and after treatment, and at the time of reducing dose and turning to maintenance dose of prednisone. The therapeutic effect of the two groups were also observed. Another group of 30 healthy person was established for control. RESULTS: The difference of TXB2, 6-Keto-PGF1 alpha, ET, CGRP between patients and healthy persons was very significant before treatment (P < 0.001). Above-mentioned 4 parameters improved synchronously with the clinical improvement in the therapeutic course and they were better in the TCM-WM group than those in the western medicine group (P < 0.001) and the complete remission rate of the former group was also higher than that of the latter (62.9% vs 37.1%, chi 2 = 4.63, P < 0.05). CONCLUSION: BHD could improve the therapeutic effect in treating PNS through the mechanism of improving TXB2, 6-Keto-PGF1 alpha, ET and CGRP levels.

6-Ketoprostaglandin F1 alpha↗

PubMed1998

[Clinical study on buyang huanwu decoction to the metabolic imbalance of endothelin and calcitonin gene related peptide in patients with early cerebral infarction].

OBJECTIVE: To explore the mechanism of Buyang Huanwu Decoction (BHD) in treating early cerebral infarction. METHODS: Seventy cases with early cerebral infarction were randomly divided into two groups. Chinese medicine group (CMG, n = 35) was treated with BHD; western medicine group (WMG, n = 35) was treated with hydroxyethyl starch injection and enteric coated aspirin tablets. The levels of endothelin (ET) and calcitonin gene related peptide (CGRP) in plasma before and after treatment and the results of clinical treatment were observed, and also controlled with healthy subjects. RESULTS: The levels of ET before treatment in both patient groups were significantly higher than that of the healthy subjects (P < 0.001), and the levels of CGRP were significantly lower (P < 0.001). After treatment the metabolic imbalance of ET and CGRP improved significantly in both treatment groups (in CMG P < 0.001; in WMG (P < 0.01), but the ET and CGRP in CMG improved more obviously than those in WMG (P < 0.01, P < 0.05). The marked effective and cure rate of CMG was higher than that of WMG (68.6% vs 31.4%; chi 2 = 9.65, P < 0.01). CONCLUSIONS: BHD could improve the metabolic imbalance of ET and CGRP in patients with early cerebral infarction and by this mechanism it was able to treat cerebral infarction.

Adult↗

PubMed1998

[Effect of fighter cockpit noise on pilot hearing].

In order to describe quantitatively the pilots' hearing injury by noise in fighter cockpit, the noise level was measured in the cockpit. The temporary threshold shift (TTS) was studied in 20 healthy young man and permanent threshold shift was examined in 166 fighter pilots. The results showed that noise level in cockpit was 110 dBA and TTS after 2 min noise exposure decreased significantly and reached 13 dB at a certain frequency. Its recovery course is faster in low frequency part and language frequency part than that in high frequency part. It was also found that 56% of the 166 pilots suffered from high frequency hearing loss and the percentage increased with flight time. The feature of hearing loss is that it occurs in high frequency at first, then in language frequency, forming a "V" shaped depression at 6 000 Hz. It indicates that cockpit noise may cause permanent threshold shift of hearing.

Adolescent↗

PubMed1998

Sensitization of acnu killing effects on HeLa S3 cells by MGMT antisense RNA transfection.

O6-methylguanine-DNA-methyltransferase (MGMT) plays a very important role in the cellular resistance to nitrosoureas drugs. Inhibition of MGMT might be a useful approach in tumor chemotherapy. In this study, the depletion of MGMT activity by retroviral-mediated antisense RNA transfection were reported. Three retroviral vectors expressing MGMT antisense RNA were constructed and transfected into HeLa S3 cells. The difference of MGMT mRNA, MGMT activity as well as cellular resistance to ACNU before and after transfection were observed. It was found that antisense RNA targeting 5' region and whole length of MGMT mRNA could partially deplete MGMT activity and enhance killing effects of ACNU. However, 3' region antisense RNA had no effect on MGMT modulation.

Antineoplastic Agents↗

PubMed1998

[Isolation and cloning of expressed sequences in a region flanking ANK1 on human chromosome 8p11.2].

OBJECTIVE: Our efforts were to isolate expressed sequences in a region flanking ANK1 on chromosome 8p11.2. METHODS: cDNA selection method was applied to isolate the expressed sequences from yeast artificial chromosomes(YAC) mapped to the region flanking ANK1 and one of the expressed sequences was isolated for the screening for human fetal brain cDNA library. RESULTS: Seven cDNA sequences were identified. Of these sequences, five were mapped back to their corresponding YAC. The remaining two sequences (BHLC26 and BHLC181) did not hybridize to any YAC used. BHLC152 was highly homologous to a gene for the musculus CArG box-binding factor. BHLC74 shared substantial identity with the gene encoding ventricular myosin alkali light chain 1 (MLC1), indicating that it might encode a MLC1 isoform. Partial sequence from other expressed sequences bore homology with some expressed sequences tagged with unknown function and without mapped data in the databases. BHLC119 was used as probe to screen cDNA libraries. One positive clone was sequenced. Its insert is 1,951 bp in length and encode a predicted 174 amino acids without homology with known proteins. One transcript of 3.5 kb was detected in total RNA from human fetal brain by Northern blotting. Tissue expression analysis suggests that it is a widely-expressed gene. CONCLUSION: BHLC74 may be considered a candidate gene for the 8p-related heart diseases. Other expressed sequences isolated might be used at least as candidates screening preliminarily for the tumor suppressor gene mapped to the region flanking ANK1 on 8p11.2.

Amino Acid Sequence↗

PubMed1998

[Retroviral-mediated transcriptional regulatory elements of alpha-fetoprotein gene directed specific expression of interleukin-2 in murine hepatoma].

OBJECTIVE: To target expression of interleukin-2 in alpha-fetoprotein (AFP) positive hepatocellular carcinoma. METHODS: A retroviral vector pDOR-mAFP-IL2 was constructed by coupling the transcriptional regulatory elements (TREs) of murine AFP gene with interleukin-2 cDNA in a retroviral vector. RESULTS: Subsequent to retroviral infection, expression of IL-2 could be detected in an AFP positive murine hepatoma cell line Hepa1-6 but not in psi 2, an AFP negative murine fibroblast cell line. CONCLUSIONS: Our results indicate that specific expression of IL-2 in hepatoma cell can be achieved by using of AFP TREs to control the expression of IL-2, and the retroviral vector which we have constructed may be used for further experimental studies on in vivo gene therapy.

Animals↗

PubMed1998

[The timing and mode of surgery in patients with severe acute pancreatitis].

OBJECTIVE: To investigate the timing and mode of surgical management in patients with severe acute pancreatitis (SAP). METHOD: The timing, mode of operation and mortality were reviewed retrospectively in 50 SAP cases undergoing laparotomy in our hospital from 1985 to 1994. RESULT: The overall mortality was 14% and 85.7% of the mortality falls on the age between 40 to 60 years, with no difference in etiology and sex. The operative mortality reduced gradually in patients with longer duration of illness (P > 0.05). The operative mortality of 31.8% in patients undergoing laparotomy within 12 h after hospitalization was significantly higher (P < 0.05) than in these operated on later. When the number of injured extra-pancreatic organs increased, the mortality also increased significantly (chi(2) = 5.99, P < 0.05). The related mortality with shock, pancreatic necrosis and multiorgan failure (MOF) was 31.8%, 31.6% and 28%, respectively (P < 0.05). The main procedures of surgical management were pancreatic debridement and/or drainage, and combined surgical measures. CONCLUSION: The laparotomy timing is an important factor influencing mortality as well as the severity of pancreatic necrosis, sepsis, and MOF. Delayed laparotomy and 24 h preoperative management is recommended. Surgery adopted should be simple, efficient in drainage and debridement.

Adolescent↗

PubMed1998

[Treatment of old femoral neck fracture with implantation of a vascularized fibular graft].

OBJECTIVE: To investigate the healing of old femoral neck fracture treated with transplantation of vascularized fibula graft accompanied with lag screw, and rehabilitation of and precaution against ischemic necrosis of femoral head. METHOD: Vascularized fibula autograft was transplanted to the anterolateral side of the femoral neck with an internal fixator of lag screw. Fibular artery and vein were anastomosed with lateral circumflex artery and vein. RESULT: 186 of 229 cases subjected to systemic X-ray films and function follow-up (3 to 15 years). The percentage of fracture healing was 93.0% the sulass rate 86.5%. CONCLUSION: Fibula with blood supply and compressed screw have a combined fixation effect of the old femoral neck fracture. Fibula is solid enough for supporting the femoral head and preventing it from collapse. Vascularized fibular grafting provides blood supply to the affected femoral head and neck, promoting femoral head restoration and reconstruction.

Adolescent↗

PubMed1998

[Coexisting pheochromocytoma and renal artery stenosis].

OBJECTIVE: To improve the diagnosis of coexisting pheochromocytoma and renal artery stenosis. METHOD: Four patients with coexisting pheochromocytoma and renal artery stenosis were treated. RESULT: After removal of the pheochromocytoma, the blood pressure became normal in two patients combined with resection of kidney with renal artery stenosis, and one patient with local adhesion loosened. The hypertension, however, persisted in another patient after the resection of pheochromocytoma even though the long segment of renal artery stenosis was relieved. CONCLUSION: After pheochromocytoma was diagnosed with its known position, coexisting renal artery stenosis should be suspected according to one of the following conditions: (1) Vascular murmurs are noted at the area of the upper abdomen or back; (2) One of the kidneys becomes less sized; (3) Using the inhibitor of receptor alpha only has no effect lowering blood pressure and it is necessary to add the inhibitor of angiotension; (4) Postoperative hypertension does not resolve when no remaining pheochromocytoma is present. the renal artery stenosis can be reversed after both removal of pheochromocytoma and loosening of adhesion in case of stenosis due to the pressure of the tumor and adhesion caused renal artery angling and local stricture. Extensive stenosis or closure, however, can not be corrected with severe atrophy of renal parenchyma due to pheochromocytoma, and the resection of kidney should be indicated.

Adolescent↗

PubMed1998

[Long-term results of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension].

OBJECTIVE: To investigate the long-term effects of combined splenorenal shunt and porta-azygos devascularization in patients with portal hypertension. METHOD: We analysed retrospectively the follow-up results of 140 portal hypertensive patients undergoing the combined therapy in our hospital from April 1978 to April 1997. Changes of portal hemodynamics were studied by Doppler Flowmeter and DSA pre- and-postoperatively and direct FPP measurement intraoperatively. RESULT: The operative mortality was 3.6%. No rebleeding was noted in a short period and rebleeding rate was 8.3% in a long term follow-up. The rate of postoperative hepatic encephalopathy was 5.0%. The long-term survival rate of 5-, 10- and 15-years was 83.6%, 64.5% and 54.5%, respectively. After operation FPP and PVP decreased significantly (P < 0.01) and FPP maintained at the level of 3.2 +/- 0.4 kPa. CONCLUSION: The combined procedure is a rational and practical procedure for the treatment of patients with portal hypertension.

Adolescent↗

PubMed1998

[The effect of chitosan in prevention of fibrous scar tissue formation after laminectomy].

OBJECTIVE: To study the effect of chitosan in the prevention of fibrous scar formation in the epidural space after laminectomy. METHOD: Fourty-eight SD rats were used as the animal model. Laminectomy was performed in lumber 1, and the exposed dura was covered with hyaluronate (group A), free fat (group B), chitosan (group C), and saline solution (group D) respectively. At 4, 8 and 12 weeks postoperation, scar formation was observed. RESULT: The results revealed that scar formed in the group D at the fourth week reached a peak at the eighth week and began to soften and constrict at the twelfth week. Sodium hyaluronate and chitosan had a significant efficacy in the prevention of scar formation, but the effect of chitosan was superior to that of sodium hyaluronate. CONCLUSION: The findings of this study indicate that chitosan has a preventive effect on scar tissue formation.

Animals↗

PubMed1998

[Unreamed interlocking intra medullary nailing in treating tibial and fibular fractures].

OBJECTIVE: To report the experience in the use of unreamed interlocking intramedullary nails. METHOD: From 1995 to 1997, 54 tibial and fibular fractures were treated with unreamed interlocking intramedullary nails they included open fractures (9 cases) and close fractures (45). RESULT: All fractures healed within 6 months and showed good knee and ankle joint functions. Slight postoperation infection was found in one of the open fractures. Incomplete injury of peroneal nerve was noted in 1 case. CONCLUSION: Unreamed interlocking intramedullary nail can be used to treat diaphyseal fractures effectively. It can protect the soft tissue envelope around the fracture and prerent local blood supply from further damaginge.

Adolescent↗

PubMed1998

[Carboplatin drug concentration in tumor tissues by intraperitoneal chemotherapy].

OBJECTIVE: To investigate drug concentration in tumor tissues after intraperitoneal chemotherapy with carboplatin. METHOD: High performance liquid chromatography was used to study the pharmacokinetics of carboplatin in 10 patients with resectable advanced gastric cancer after intraperitoneal chemotherapy. 300 mg/m(2) carboplatin in 750 ml 0.9% sodium chloride were intraperitoneally injected. After 160 - 180 minutes, peritoneal fluid, blood of portal vein and peripheric blood were collected. 240 - 270 minutes later, cancer tissues, normal tissues, peritoneum, omentum, and normal lymph nodes were taken. The total carboplatin concentrations were measured. RESULT: Drug concentration was highest in the peritoneal fluid, followed by that the in blood of portal vein. They were 8 times, 1.6 times of the concentration in peripheric blood. The concentration in the peritoneum was higher than in other tissues (P < 0.05). The concentration in tumor tissues was higher than that in normal tissues. CONCLUSION: Intraperitoneal chemotherapy with carboplatin chemotherapy increased its concentration in the peritoneal cavity and the blood of portal vein, and its accumulation in the peritoneum and tumor tissues, which help eliminate subclinical lesions, improve clinical stage, control iatrogenic metastasis, and increase resectable rate.

Adult↗

PubMed1998

[The significance of changes in serum soluble lipopolysaccharide receptor CD14 levels in burned patients with multiple organ dysfunction syndrome].

OBJECTIVE: To determine whether an increased soluble lipopolysaccharide receptor CD14 (sCD14) level is associated with the development of multiple organ dysfunction syndrome (MODS) in patients after major burns. METHOD: 22 patients with burns covering more than 70% of body surface area were studied. These patients were divided into two groups according to the occurrence of MODS (MODS group, n = 9; non-MODS group, n = 13). Blood samples were obtained from burned patients. Serum concentrations of sCD14 and tumor necrosis factor (TNF) were determined by sandwich ELISA. Plasma endotoxin was measured using a quantitative chromogenic LAL test. RESULT: Compared to the healthy volunteers, a significant increase in serum sCD14 levels was observed in 22 patients on day 7 postburn, which remained marked elevation up to 21 days after thermal insult (P < 0.01). The serum sCD14 levels of the MODS group were significantly higher than those of the non-MODS group on days 7, 14, and 21 postburn (P < 0.05). Additionally, the serum sCD14 and endotoxin levels were positively correlated in patients who developed MODs on days 7, 14 and 21 postburn (P < 0.05), whereas no correlation was found between sCD14 and TNF levels at any time point (P > 0.05). CONCLUSION: Our data suggest that sCD14 elevation is associated with the development of MODS after major burns, and endotoxin release may be involved in the activation of sCD14 under certain pathophysiological conditions.

Adolescent↗

PubMed1998

[Long-term outcome of selective posterior rhizotomy for spastic cerebral palsy].

OBJECTIVE: To investigate the long term outcome and complication of selective posterior rhizotomy for spastic cerebral palsy. METHOD: 26 patients with cerebral palsy who had received SPR were followed up for four years. RESULT: In the 9 patients who could walk and stand up from squatting position independently, 7 could stand steadily on one foot after operation. In the 12 who patients could walk and stand up from squatting position dependently, 7 could walk independently in the room after operation. In 5 patients couldn't walk and stand up from squatting position, 3 patients could walk dependently in the room after operation. Complications occurred in 3 patients. CONCLUSION: Selective posterior rhizotomy is effective in the treatment of spastic cerebral palsy. Strictly selecting candidates for the operation and good rehabilitation training before and after operation should be emphasized for good results.

Cerebral Palsy↗

PubMed1998

[A study of the gene encoding Ki-67 antigen in human pancreatic cancer using non-radioactive in situ hybridization and immunohistochemistry].

OBJECTIVE: To investigate, at transcriptional and translational level in situ, the abnormal gene expression of the Ki-67 protein in pancreatic carcinoma specimens. METHOD: 40 pancreatic cancer specimens, 5 normal pancreatic and 4 chronic pancreatitis tissues were studied. A 435 bp cDNA fragment located in codon 2, exon 13 of the Ki-67 antigen gene was amplified by the polymerase chain reaction (PCR). The DIG-labeled cRNA probes were transcribed using a commercially available DIG RNA labeling kit. Localization of the Ki-67 protein and the specific mRNA were studied by combining immunohistochemistry (ICH) with (DIG)-labeled in situ hybridization (ISH). RESULT: The Ki-67 protein mRNA in formalin-fixed and paraffin-embedded pancreatic tissue sections was successfully localized. Analyzing the Ki-67 mRNA transcription in 17 pancreatic cancer specimens with Ki-67 ICH labeling index > 20%, we found that stronger mRNA signals were also observed in poorly differentiated specimens with Ki-67 index > 50% than in those well differentiated with ICH labeling index 20% - 50%. A high expression of both mRNA and protein was observed in poorly differentiated pancreatic adenocarcinomas. CONCLUSION: Abnormal overexpression of the gene encoding Ki-67 protein was detected not only at the protein level, but also at the mRNA level in pancreatic tumors. The abnormal overexpression of the Ki-67 protein might be correlated with the central part, exon 13, of the gene.

Female↗