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Biomedical subjects

D Chen

Publications and source records attributed to D Chen.

At least 253 records · Page 14Linked to original sources
PubMed2000

Design and clinical application of cervical hollow threaded fixator.

OBJECTIVE: Cervical hollow threaded fixator (CHTF) was designed and applied to stabilize the cervical spine following anterior decompression due to cervical spondylosis or acute cervical disc herniation. METHODS: Medical use titanium alloy with no magnetism was made into a hollow threaded structure with holes on the wall of the fixator. Forty-two patients with cervical spondylosis and acute cervical disc herniation were stabilized using the CHTF technique after anterior decompression. X-ray films and CT scans were taken after the operation to observe the stability and fusion rate of the segments. RESULTS: Patients were allowed to walk one day after the operation and were followed up for 6 to 36 months. The operated segments were stable and solid fusion was observed 3-6 months after surgery. CONCLUSIONS: Immediate stability of the operated segments can be obtained using the CHTF technique. Patients were easy to manage after the operation and returned to their jobs in a short time. The CHTF technique is safe and simple to perform and eliminates the complications of an autograft. It may be an alternative to traditional cervical interbody fusion with bone graft.

Adolescent↗
PubMed2000

[Clinical study on effect of Tripterygium wilfordii Hook. f. on uterin leiomyoma].

OBJECTIVE: To observe the therapeutic effect of Tripterygium wilfordii Hook. f. on patients with uterine leiomyoma. METHODS: Baseline ultrasound examinations of myomas and uterine were obtained and repeated three months, six months after treatment. Blood samples were collected in the mid-follicular or mid-luteal phase of the menstrual cycle before initiation of Tripterygium wilfordii Hook. f. therapy and after treatment 3-4 months and 5-6 months, for determination of estradiol, progesteron, testosterone, follicle-stimulating hormone, luteinizing hormone and prolactin by radioimmunoassay. RESULTS: Significant decrease in leiomyoma volume was detected in 39 of 65 (60.0%) patients after 3-4 months of Tripterygium wilfordii Hook. f. treatment and 28 of 40 (70.0%) patients after 5-6 months of treatment. The decrease in leiomyoma volume with Tripterygium wilfordii Hook. f. treatment was time-dependent while 27.84% in 3-4 months, 51.6% in 5-6 months. 25 of 65 patients were amenorrheic during the course of treatment. Compared with pretreatment values, Tripterygium wilfordii Hook. f. treatment induced an increase in mean luteinizing hormone, fdlicle-stimulating hormone levels and a decrease in mean estradiol, progesterone levels. CONCLUSIONS: Tripterygium wilfordii Hook. f. may be an effective therapeutic agent for leiomyomas with fewer side effects. Tripterygium wilfordii Hook. f. treatment showed a reversibly inhibitory effect on the ovary. It may be one of the mechanisms of Tripterygium wilfordii Hook. f. in decreasing leiomyoma volume.

Estradiol↗
PubMed2000

[Clinical and experimental study on effect of rhubarb on gastrointestinal blood flow perfusion].

OBJECTIVE: To study the effect of rhubarb on gastrointestinal (GI) perfusion in critical illness and hemorrhagic shocked rats. METHODS: Clinical study: Sixty-four septic patients suffered from stress ulcer were treated with rhubarb at a dose of 25 mg/kg, 25 non-septic patients were taken as control. The GI perfusion was evaluated by intramural pH. Animal study: SD rats were anesthetized with intraperitoneal sodium pentobarbital at a dose of 20 mg/kg. Then the animals were blood-letting, the blood pressure reduced to 5.32 kPa and maintained for 120 minutes. They were resuscitated at the end of shock by reperfusing all the shed blood. The rats were divided into four groups: normal control, shock group, treated group (shocked rats were treated with 50 mg/kg rhubarb by the end of shock), and rhubarb group (normal rats were treated with rhubarb). Laser Doppler determination was applied to estimate the GI perfusion. RESULTS: Clinical study: The pH in septic patients was much lower than that in the control, whereas rhubarb could obviously elevate GI pH (P < 0.01). In addition, rhubarb also had a good effect on gastric hemorrhage caused by stress ulcer, the effectiveness was 73.4%. Animal study: Although the shocked rats were resuscitated completely, their GI perfusion was much lower than that in the control. Rhubarb could significantly improve the mucous membrane of GI and mesenterium perfusion (P < 0.01). Furthermore, rhubarb also increased the GI perfusion in normal rats. CONCLUSION: The rhubarb could improve the GI blood perfusion in critical illness and shocked rats.

Adolescent↗
PubMed2000

[The relationship among proinsulin and true insulin to coronary artery disease].

OBJECTIVE: Whether proinsulin (PI) and true insulin (TI) are independently related to coronary artery disease (CAD). METHODS: 54 patients with CAD diagnosed by coronary angiography and/or intravascular ultrasound, 37 patients without CAD by coronary angiography and/or intravascular ultrasound and 23 healthy volunteers. All subjects had oral glucose tolerance test after an overnight 14 h fast. PI and TI concentrations were detected at different phases by BA-ELISA in which PI cross -reactivity is less than 0.1%. RESULTS: Fasting and post-glucose loading PI and TI levels in both CAD and non-CAD groups significantly increased when compared with the control group (P < 0.05), after adjustment for age, body mass index and waist hip ratio, all statistically significant associations weakened or disappeared among three groups; but there was no significant difference of all the above variables between CAD group and non-CAD group (P > 0.05). CONCLUSION: PI and TI, whether fasting or post-glucose loading, may not be independently related to CAD.

Adult↗
PubMed2000

[Anterior corpectomy combined with cervical spine locking plate for treatment of multilevel cervical spondylotic myelopathy].

OBJECTIVE: To study the value of cervical spine locking plate (CSLP) combined with anterior corpectomy in treating multilevel cervical spondylotic myelopathy (CSM). METHODS: In 55 CSM patients, 36 were male and 19 female, aged on average 51.5 years. The duration of illness was 13 months on average. Pathological segments in 47 patients included two functional segments and in 8 three functional segments. All patients were treated with anterior corpectomy and self-iliac bone graft and CSLP fixation. RESULTS: 51 patients were followed up for 26 months on average. All grafting bones got solid fusion in 12 to 16 weeks postoperatively. Intervertebral spaces were restored after operation. The physiological curve of the cervical spine was good. The effective rate of operation was 94.1% (48/51) and the excellent rate 78.4% (40/51). The JOA score rose from 8.3 points before operation to 14.1 points after operation. CONCLUSIONS: Anterior corpectomy and osteosynthesis of multilevel cervical spondylotic myelopathy are indicated for CSLP fixation. CSLP in the treatment of cervical spine instability is prospective.

Aged↗
PubMed2000

[The study of RDS gene mutation and clinical phenotype in a family with primary retinitis pigmentosa].

OBJECTIVE: To investigate retinal degeneration slow (RDS) gene mutation in a Chinese family with primary retinitis pigmentosa (RP) and the association of the mutation with clinical phenotypes and to explore the pathogenesis of RP. METHODS: Blood DNA from 2 patients in the same family with RP and 2 normal persons was analyzed by molecular genetic methods. RDS gene mutation was screened out by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The mutant RDS gene fragment was cloned, then sequenced with an automatic DNA sequencer using a dideoxy chain termination protocol. The phenotype of the patients with the gene mutation were examined and determined by clinical ophthalmologic examinations. RESULTS: The PCR-RFLP analysis of the RDS gene in 2 patients with RP revealed codon 216 mutation of RDS gene. The mutation was heterozygous, and not found in 2 normal persons as controls. The alteration in the DNA sequence was identified as a heterozygous transversional change of C to T at the second nucleotide in codon 216 of RDS gene, resulting in the amino acid replacement of proline residue with leucine residue (Pro216Leu). The ocular finding of the patients with Pro216Leu mutation of RDS gene included severe visual loss and diffuse distribution of pigmentary changes with macular degeneration. CONCLUSIONS: The Pro216Leu mutation of RDS gene is found in Chinese patients with RP. The gene mutation is associated with the ocular phenotype, diffuse RP with macular degeneration.

Adult↗
PubMed2000

[p16, p53 and c-erbB-2 gene expression in bladder carcinoma].

OBJECTIVE: To investigate the expression of p16, p53 and c-erbB-2 proteins in bladder carcinoma and to analyze their correlation with tumor grade, clinic stage and metastasis. METHODS: Immunohistochemical method was used to detect the p16, p53 and c-erbB-2 gene expressions in 75 cases of bladder carcinoma. RESULTS: Positive rates of p16, p53 and c-erbB-2 in 75 cases of bladder cancer were 41.3%, 44.0% and 40.0%, respectively. p16 and c-erbB-2 gene expressions were related to the tumor grade and clinic stage (P < 0.05); p53 and c-erbB-2 gene expressions were related to the clinic stage and metastasis (P < 0.01). Oncogenes and/or antioncogenes altered expressions were found in 77.3% cases of bladder carcinoma, and oncogenes and/or antioncogenes with multiple altered expressions were found in 53.3% cases. CONCLUSION: The analysis of multiple oncogene and/or antioncogene is more valuable than that of single oncogene and/or antioncogene. The altered expression of oncogene c-erbB-2 and antioncogenes p16 and p53 might play a promotive role in the tumorigenesis and development of bladder tumors.

Adult↗
PubMed2000

[Effect of rhubarb on oxygen radicals leakage from mitochondria of intestinal mucosa in burned rats].

OBJECTIVE: To investigate the effects of rhubarb on oxygen radicals leakage from the mitochondria of intestinal mucosa in burned rats. METHODS: The activity of cytochrome oxidase and superoxide dismutase (SOD) in mitochondria isolated from intestinal mucosa of burn model of rats was used to evaluate the oxygen radicals leakage from the mitochondria. And the SOD and malondialdehyde (MDA) levels in plasma, liver, intestinal mucosa and its mitochondria were also determined. RESULTS: After burn injury, the activity of cytochrome oxidase in intestinal mucosa decreased as the time elapses, rhubarb could improve it obviously. Furthermore, rhubarb could reduce the massive consumption of SOD and production of MDA obviously increased in plasma, liver, intestinal mucosa and its mitochondria after burning. CONCLUSION: Rhubarb could enhance the activity of cytochrome oxidase and SOD in small intestine mucosal epithelia in burned rats, thus the oxygen radicals leakage from the mitochondria to be reduced.

Animals↗
PubMed2000

[Inhibition of the activation and collagen production of cultured rat hepatic stellate cells by antisense oligonucleotides against transforming growth factor-beta 1].

In order to investigate whether the antisense oligonucleotides (ASON) against TGF beta 1 inhibit the activation and collagen production of cultured rat hepatic stellate cells, the authors synthesized two 20-mer phosphorothioate antisense oligonucleotides and their sense or missense oligonucleotides, and then treated the rat hepatic stellate cells (HSC) with these oligonucleotides at different concentrations respectively. HSC activation was assessed by the expression of alpha-smooth muscle actin (alpha-SMA), and TGF beta 1 level was determined by a standard bioassay. The production of collagen was measured by the incorporation of 3H-Proline into cultured rat HSCs. The results showed that the ASON against the translation initiation region of TGF beta 1 at a final concentration of 10 mumol/L could inhibit the HSCs activation, the secretion of TGF beta 1 and the production of collagen in HSCs significantly (P < 0.05), whereas the controls (sense or missense oligonucleotides) had no effect at the same concentration. All of the oligonucleotides had no cytoxicity to HSCs. These findings suggested that TGF beta 1 ASON might be useful for the treatment of hepatic fibrosis.

Actins↗
PubMed2000

[Inhibition of the activation and collagen production of cultured rat hepatic stellate cells by antisense oligonucleotides against transforming growth factor-beta 1 is enhanced by cationic liposome delivery].

In order to investigate the inhibition of the activation and collagen production of cultured rat hepatic stellate cells (HSC) by antisense oligonucleotides (ASON) against TGF beta 1 after cationic liposome (lipofectin) delivery, the authors synthesized a 20-mer phosphorothioate antisense oligonucleotide of TGF beta 1 mRNA, and its sense of missense oligonucleotides, and then treated the HSC with cationic liposome/oligonucleotide complexes respectively. The cellular uptake of 32P-labelled oligonucleotides was determined by liquid scintillation counting, and HSC activation was assessed by the expression of alpha-smooth muscle actin(alpha-SMA). The cellular uptake of lipofectin/32P-ASON complex was approximately five-fold higher than that of 32P-ASON alone. Cationic liposome (lipofectin) delivery significantly increased the inhibition of HSCs activation by ASON, while compared with the use of naked TGF beta 1 ASON at the same concentration (at a final concentration of 1 mumol/L, P < 0.05). However, these effects were not observed in lipofectin alone, liposome/sense or missense oligos complexes at the same concentration. The oligonucleotide or lipofectin/oligos complexes had no cytotoxicity to rat HSCs in culture. These findings suggest that cationic liposome is an effective vehicle to improve the delivery of ASON to rat HSCs in culture, and the cationic liposome/TGF beta 1 ASON complex may be useful for the treatment of hepatic fibrosis.

Actins↗
PubMed2000

[The relationship between arteriolar pathological changes and brain hemorrhage in primary hypertension cases].

This study was intended to elucidate the relationship between arteriolar pathological changes and encephalorrhagia in the cases of primary hypertension. Gross anatomy and histology of brain were observed in autopsy of 45 cases of primary hypertension. Forty cases of arteriolar hyalinization including 26 cases of brain hemorrhage were found in those 45 cases of primary hypertension. The hyalinized arterioles were divided to two types. One is characterized by the narrow lumen of terminal arterioles, the other by the dilatant lumen of proximal arterioles. Hemorrhage always occurred in the latter type. Besides these changes, 3 cases of acute necrosis and 5 cases of atherosclerosis in arterioles were related to hemorrhage. These data suggest that brain hemorrhage of primary hypertension mainly occur in dilated and hyalinized arterioles, and some cases are probably related to acute necrosis or atheroscleromatous atrerioles.

Adult↗
PubMed2000

[Arsenic trioxide induced human esophageal cancer Ec109 cell apoptosis with downregulation of c-myc gene expression].

OBJECTIVE: To study effect of downregulation of c-myc gene expression with As2O3 on inducing Ec109 cell apoptosis. METHODS: MTT reduction assay, flowcytometric analysis, DNA gel electrophoresis, Western blot and in situ cell death detection (TUNEL). RESULTS: The viability of the cells treated with As2O3 was decreased. The cells treated with As2O3 showed a typical apoptotic morphology and hypodiploid peak before G1 phase. DNA of treated Ec109 cells appeared a ladder pattern characteristic of apoptosis. TUNEL detection analysis also revealed the DNA fragmentation and As2O3 decreased c-myc gene expression was observed. CONCLUSIONS: As2O3 can induce Ec109 cell apoptosis with downregulation of c-myc gene expression.

Antineoplastic Agents↗
PubMed2000

Serum levels of vascular endothelial growth factor in patients with angina pectoris and acute myocardial infarction.

OBJECTIVE: To determine whether serum vascular endothelial growth factor (VEGF) concentrations are altered in several kinds of coronary heart disease patients. MATERIALS AND METHODS: Using a VEGF enzyme-linked immunosorbent assay (ELISA), serum VEGF concentrations were determined in antecubital venous blood of 16 patients with stable angina pectoris (SAP), 16 with unstable angina pectoris (UAP) and 16 with acute myocardial infarction (AMI) before and after thrombolytic therapy, and of 16 age- and sex-matched healthy volunteers who used as controls. RESULTS: The concentrations of serum VEGF in patients with SAP (98.60 +/- 26.99 pg/ml) and UAP (103.61 +/- 24.89 pg/ml) tended to be higher than those in control subjects (80.44 +/- 24.57 pg/ml), but the differences did not reach statistical significance (P > 0.05 for each). Before thrombolytic therapy, the concentrations of serum VEGF in patients with AMI (285.92 +/- 125.15 pg/ml) were significantly higher than those in patients with SAP, UAP or control subjects (P < 0.01, respectively), and correlated with synchronous serum creatine kinase (CK) and its MB isoenzyme (CK-MB) contents (r = 0.866, P < 0.001 and r = 0.948, P < 0.001; respectively). Three hours after thrombolysis, the concentrations of VEGF had fallen to 111.57 +/- 31.29 pg/ml (P < 0.01 vs x before thrombolytic therapy and P < 0.05 vs x control subjects). CONCLUSION: The present study shows that serum concentrations of VEGF in patients with AMI are markedly elevated and that increased serum VEGF levels may be one of the most sensitive indexes in diagnosing AMI and judging reperfusion.

Adult↗
PubMed2000

[The synthesis and spectral study of multicomponent heteropoly compounds with Keggin structure].

The Multicomponent heteropoly compounds [Me4N]3 + x[PVxMoyW12-x-yO40]. n(H2O) with Keggin structure have been synthesized, and have been characterized by FTIR and NIR FT-Raman. The vibrational regularity of oxygen-containing bonds (P-Oa, M = Od, M-Ob-M and M-Oc-M) in these heteropoly compounds have been studied. The vibrational frequencies nu as (M = Od) and nu as (M-Ob-M) was shown to prove the reason why the acidity of the heteropoly compounds descended and the oxidization increased by the substitution of V atoms.

English Abstract↗