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Biomedical subjects

S Li

Publications and source records attributed to S Li.

At least 523 records · Page 29Linked to original sources
PubMed2000

[Long-term results of total versus partial laryngectomy for the treatment of squamous-cell carcinoma of the larynx].

OBJECTIVE: To analyze the long-term effects of total versus partial laryngectomy for the treatment of squamous-cell carcinoma of the larynx. METHOD: Of 423 patients with laryngeal carcinoma surgically treated, 327 had supraglottic cancer and 96 had glottic cancer. Total laryngectomy was performed in 243 patients (210 supraglottic and 33 glottic cancers) and partial laryngectomy in 180 patients (117 supraglottic and 63 glottic cancers). RESULTS: The overall 5-year survival rate of patients with supraglottic carcinoma was 72.9%. That of patients treated by total and partial laryngectomy was 70.1% and 77.4%, respectively (P > 0.05). The overall 5-year survival rate of patients with glottic carcinoma was 86.0%. That of patients treated with total and partial laryngectomy was 72.2% and 92.3%, respectively (P < 0.05). CONCLUSION: The long-term result of partial laryngectomy for glottic carcinoma is as good as total laryngectomy, and for supraglottic carcinoma, partial laryngectomy is superior to total laryngectomy. Partial laryngectomy is recommended to treat patients with squamous-cell carcinoma of the larynx. Patients so treated have a better quality of life.

Adolescent↗
PubMed2000

[Development of a video system for three-dimensional cephalometry and dental cast analysis].

OBJECTIVE: The purpose of this article is to introduce the outline of our newly developed video system for three-dimensional cephalometry and dental cast analysis. METHODS: The video measuring technique was utilized in the field of dentistry in our study. Two CCD cameras were used to capture the images both of the dental cast and headfilms. The dental cast analysis and three-dimensional cephalometry shared a set of operating system. The three-dimensional reconstruction was based on the LAT and PA films. RESULTS: The measurement error of dental cast analysis is less than 0.09 mm, and the error of three-dimensional cephalometry is less than 0.45 mm. CONCLUSIONS: The clinical application suggests that the use of our system is feasible not only for clinical evaluation of malocclusion but also for saving time necessary for treatment planing and diagnosis.

Cephalometry↗
PubMed2000

[The role of bcl-2 and bax genes and programmed cell death in the temporomandibular joint development].

OBJECTIVE: To evaluate the roles of bcl-2, bax gene and programmed cell death(PCD) in the TMJ development. METHODS: PCD, expression of both mRNA and protein of bcl-2 and expression of bax protein were observed by Tdt-mediated dUIP nick end labeling (TUNEL), mRNA in situ hybridization and immunohistochemical staining in TMJ of SD rats during series prenatal and postnatal developmental periods. RESULTS: PCD was involved in condylar cartilage in development of different periods. The cells of PCD were mainly located in proliferative zone and the area between prehypertrophic zone and late hypertrophic zone. bcl-2mRNA was expressed with high levels in proliferative and prehypertrophic zones and very few matured chondrocytes expressed bcl-2. The expression of bcl-2 protein showed the same distribution as bcl-2mRNA, but gradually decreased in late hypertrophic zone, compared with strong expression of Bax throughout condylar cartilage. CONCLUSIONS: PCD of condylar cartilage is regulated by bcl-2 and bax gene, the number and site of PCD are attributed to the change of bcl-2 and bax gene, and bcl-2 is an important gene in maintaining survival of chondrocytes during the proliferation, differentiation and maturation.

Animals↗
PubMed2000

[Histologic study of the temporomandibular joints after ovariectomy in rats].

OBJECTIVE: To investigate histologic changes of the temporomandibular joints (TMJ) after ovariectomy in adult rats. METHODS: Sixty-eight female SD rats aged twenty weeks were assigned to 2 groups. One group underwent bilateral ovariectomies served as experimental group. The other underwent sham ovariectomy served as control group. The rats were killed at the intervals of 1, 2, 4, 8 and 12 weeks postoperatively. Histologic observation of the TMJ was performed in a synchronous manner by using light microscopy(LM), scanning electron microscopy(SEM) and transmission electron microscopy (TEM). The serum levels of estrogen and bone mineral density of femur were also determined. RESULTS: In the experimental group, the serum levels of estrogen were obviously decreased, and bone mineral density of femur was significantly decreased at 12 weeks postoperatively. No obvious histological changes of TMJ of rats were observed at 1 and 2 weeks after the ovariectomy, whereas thickness of the condylar cartilage was increased, with irregular shape of chondrocytes at 4 and 8 weeks postoperatively. A serial of degenerative changes in the TMJ was observed in osteoporotic rats at 12 weeks after the ovariectomy. CONCLUSIONS: Estrogen deficiency in rats may cause alterations of the TMJ, and osteoporosis may predispose to degenerative changes in the TMJ.

Animals↗
PubMed2000

[Effect of ligustrazine injection on vascular endothelial cell of the patients with arteriosclerosis obliterans].

OBJECTIVE: To study the effect of ligustrazine injection (LI) on vascular endothelial cell of the patients with arteriosclerosis obliterans (ASO) and explore the new pathway of investigating effective vascular protective agents in Chinese medicinal herbs. METHODS: Forty-six patients with ASO in the LI group treated by LI were observed, their circulating endothelial cells (CEC) were detected quantitatively before and after treatment. The results were compared with the CEC of 53 cases of healthy persons (control group) in the same period. RESULTS: In the LI group, the immediate cure rate was 45.7% (21 cases), markedly effective rate 36.9% (17 cases) and the effective rate 17.4% (8 cases). The CEC of patients before treatment was 4.39 +/- 1.76/0.9 microliter, which was significantly higher than that of the healthy persons (1.53 +/- 0.42/0.9 microliter). It could be reduced after treatment, along with the improvement of symptoms and signs, to 2.43 +/- 0.87/0.9 microliter, P < 0.01. CONCLUSION: LI in treating ASO not only displays extraordinary effect, but also has good effect in curing the damage of endothelial cells.

Aged↗
PubMed2000

[Contrast observation on preventive effect of different traditional Chinese medicine treatments on coronary artery ligation induced myocardial ischemia in rats with diabetes mellitus].

OBJECTIVE: To compare the preventive effect of different TCM treatment on coronary artery ligation induced myocardial ischemia in rats with diabetes mellitus. METHODS: Model rats of diabetes mellitus induced by streptozotocin were used to form myocardial ischemia models by coronary artery ligation, which were treated by modified Taohe Chengqi Decoction (TCD) and different combination of its ingredients. The effect of different TCM treatment on ischemic area, arrhythmia rate and T-wave in electrocardiogram, and 2 hrs postoperational survival rate were observed. RESULTS: Effect of reducing ischemic area and raising survival rate (P < 0.05, P < 0.01) showed in all the groups treated by different TCM treatment, especially in the group treated with comprehensive TCM. Obvious improvement on T-wave revealed in the groups treated with TCD and comprehensive TCM (P < 0.05, P < 0.01). CONCLUSION: Invigorating Qi and Nourishing Yin, Expelling Heat by purgation and accentuating on activating blood circulation is an effective method of TCM in treating and preventing diabetic coronary heart disease.

Animals↗
PubMed2000

[Cytokine-induced release of plasminogen activator inhibitor-1 by human pleural mesothelial cells].

OBJECTIVE: To investigate the effects of inflammatory cytokines on the production of plasminogen activator inhibitor-1 (PAI-1) by human pleural mesothelial cells (HPMC). METHODS: Six primary cultures of HPMC isolated from patients with exudative pleural effusion were incubated in DMEM/F12 medium to examine the effect of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNFalpha) or transforming growth factor-beta1 (TGF-beta1) on the fibrinolytic properties of HPMC in vitro. The purity of the cell population was assessed by morphologic, ultrastructural and immunohistochemical characteristics. PAI-1 activity in the conditioned media of third passage HPMC was detected using chromogenic substrate method. RESULTS: As compared with the controls, PAI-1 activity in the conditioned media of HPMC increased significantly by stimulation with IL-1beta, TNFalpha or TGF-beta1 for 24 hours at the level of 0.20 microg/L (IL-1beta: q = 3.38, P < 0.05; TNFalpha: q = 4.41, P < 0.05; TGF-beta1: q = 22.03, P < 0.01), 2.00 microg/L (IL-1beta: q = 12.28, P < 0.01; TNFalpha: q = 16.60, P < 0.01; TGF-beta1: q = 19.23, P < 0.01) and 20.00 microg/L(IL-1beta: q = 24.30, P < 0.01; TNFalpha: q = 25.00, P < 0.01; TGF-beta1: q = 49.30, P < 0.01). Furthermore, HPMC responses to TGF-beta1 were significantly greater than those to IL-1beta or TNFalpha. CONCLUSION: These results suggest that inflammatory cytokines might mediate the release of PAI-1 by HPMC in vivo, affect the deposition of fibrin within the pleural cavity and favor fibrogenesis.

Adult↗
PubMed2000

[Etiological study on patients with seronegative viral hepatitis].

OBJECTIVE: To investigate the etiology of hepatitis patients who were seronegative for viral hepatitis A through E. METHODS: By using PCR, HBV DNA, HCV RNA, HEV RNA and HGV RNA were detected in sera of 104 patients with seronegative viral hepatitis. The partial nucleotide sequences of 2 HCV and 17 HEV isolates were analysed by direct sequencing. RESULTS: Among the 104 patients with seronegative viral hepatitis, the positive rates of HBV DNA, HCV RNA, HEV RNA and HGV RNA were 29.8%, 3.8%, 22.1% and 7.7%, respectively, with only 38 cases (36.6%) negative for the genome of all known hepatitis viruses. CONCLUSION: In addition to serological tests, the polymerase chain reaction of all known hepatitis viruses should be used to make the diagnosis of non-A - E hepatitis.

Base Sequence↗
PubMed2000

[The relationship between HCY-2 gene and congenital heart teratogenesis in early chick embryos].

OBJECTIVE: To explore the relationship between novel gene (HCY-2), homocysteine and congenital heart defects, and to study their biological mechanisms. METHODS: The teratogenic test of chick embryos which were treated with D.L-homocysteine (0.16 micromol/embryo) was used to observe the developmental toxicity of homocysteine per se. The eukaryotic expressing vector containing whole-length HCY-2 cDNA (2 014 bp) was microinjected into fertile eggs with lipofect AMINE(TM) reagent; then the effects of HCY-2 gene on cardiovascular damages of embryos, the expression and distribution of HCY-2 gene coding product were investigated with the techniques of Western blot, immunohistochemistry, light and electron microscopy. RESULTS: Apparently teratogenic action of homocysteine on developing heart was observed in the critical stage of organogenesis and the damages were concentration dependent (P < 0.05). 10 approximately 20 microgram HCY-2 gene could cause dysmorphogenesis of the cardiovascular system. The congenital heart defect rates were 16.7% and 24.0% respectively. The abnormal forms were ectopic cardis extrathoracic heart and hypoplastic heart. Western blot and immunohistochemical staining showed that HCY-2 protein was largely expressed in the abnormal embryos, with stronger staining at the sites of embryonic heart and brain as compared with controls. Under light and electron microscope, it was seen that HCY-2 gene resulted in structure disturbance, endocardial cushion defect and hypoplasia of heart. CONCLUSION: Homocysteine/HCY-2 gene may be a new heart-developing cytotoxic/genotoxic factor, and HCY-2 gene may play a very important role in the mechanisms of congenital heart defects of chick, and probably humans as well.

Animals↗
PubMed2000

[Abnormal P3 latency in obstructive sleep apnea syndrome, but normal in snore].

OBJECTIVE: To evaluate the P3 wave (latency, amplitude) in snorers and patients with obstructive sleep apnea syndrome (OSAS) and investigate the possible mechanism. METHODS: Three groups, OSAS patient group (n = 21), snorer group (n = 21) and control group (n = 21), were administered polysomnography (PSG), auditory evoked event-related potential (P3) and clinic memory test. The results were analyzed using GLM analysis and Post Hoc test. RESULTS: The auditory P3 latency in OSAS group was 363 ms +/- 22 ms (Fz), 369 ms +/- 28 ms (Cz), in snorer group 336 ms +/- 31 ms (Fz), 340 ms +/- 32 ms (Cz), and in control group 341 ms +/- 29 ms (Fz), 338 ms +/- 30 ms (Cz). There were significant differences between OSAS group and snorer group, as well as control group (P < 0.05). No significant difference was seen between snorer group and control group. Memory quotient (MQ) was reduced in snoren group as compared with control group. CONCLUSION: Abnormal auditory P3 latency indicates the cognitive dysfunction in OSAS patients. Nocturnal hypoxaemia may play an important role.

Adult↗
PubMed2000

[Preventing neural tube defects with periconceptional folic acid supplementation: a population-based intervention program in the China].

OBJECTIVES: To evaluate the effectiveness of periconceptional use of 400 microgram folic acid only on the prevention of neural tube defects (NTDs). METHOD: As part of a public health campaign in areas of high (North) and low (South) NTDs prevalence in the China during 1993 and 1995, 130 142 pill takers and 117 689 non-pill takers were recruited. Women were asked to begin taking a pill containing only 400 microgram of folic acid daily from the time of their premarital examination until the end of the first trimester of pregnancy. The outcomes of these pregnancies were ascertained through 1996. RESULTS: We identified 102 NTDs among offspring of pill takers and 173 NTDs among offspring of non-pill takers. The NTDs rate in offspring of non-pill takers was 4.8 per thousand (16/3 318) and 1.0 per thousand (28/28 625) in the south; while the rate in pill takers was 1.0 per thousand (13/13 012) in the north and 0.6 per thousand in the south. The greatest reduction in risk occurred among the fetuses or infants of a subgroup of women in the northern region with periconceptional use who took pills more than 80 percent of the time (reduction in risk, 85 percent as compared with the fetuses or infants of women who registered before their last menstrual period and who took no folic acid; 95 percent confidence interval, 62 to 94 percent). In the southern region the reduction in risk among the fetuses or infants of women with periconceptional use of folic acid was also significant (reduction in risk, 41 percent; 95% confidence interval, 3 to 64 percent). CONCLUSION: Periconceptional intake of supplements containing only 400 microgram folic acid can reduce the risk for NTDs in areas of high and low NTDs prevalence.

Adult↗
PubMed2000

[Genome-wide loss of heterozygosity analyses in primary hepatocellular carcinoma].

OBJECTIVE: To investigate genome-wide loss of heterozygosity (LOH) and its clinical significance in primary hepatocellular carcinoma (HCC) in southern China. METHODS: LOH on 22 autosomes was investigated with 382 sets of microsatellite markers in 65 cases of HCC. RESULTS: The average rate of informative loci was 68.1%. More than 30% LOH was detected in loci on 17p (54.1%), 4q (48.1%), 16q (43.8%), 1q (38.3%), 8p (37.2%), 13q (33.7%), and 3p (30.8%). The frequency of LOH on D4S2964 (4q13-21) in HBsAg-positive cases was significantly higher than that in HBsAg-negative cases (P < 0.05). Cases with LOH on loci both D3S3681 (3p14-21) and D17S938 (17p13) had significantly higher rates of postoporative recurrence than those without LOH on these two loci (91% and 83% vs 52% and 65%, respectively). The 3-year survival rate was significantly lower in cases with LOH than in those without LOH on D17S938 (P < 0.05). CONCLUSIONS: LOH status in HCC patients in southern China is similar to that reported in other countries and areas. However, we first identified the high frequency of LOH on chromosome 3p in HCC. Furthermore, the infection of hepatitis B virus (HBV) may be correlated with the loss of some tumor suppressor genes on D4S2964 (4q12-13), and some tumor suppressor genes may reside on loci D3S3681 (3p12) and D17S938 (17p13), relating with tumor recurrence and prognosis.

Adolescent↗
PubMed2000

[Analysis of social factors of pregnant women's cesarean section demands].

OBJECTIVE: To analyze the reasons of pregnant women's cesarean section demands. METHODS: Matched case-control study and questionnaire investigation were conducted. We analyze the cesarean section indications of pregnant women admitted to the Second and Third affiliated Hospitals of Beijing Medical University. Each section caused by pregnant woman's demand was matched with one vaginal delivery according to matching criteria. Questionnaires were used to analyze social characteristics of the two groups of women and find the reasons of women's cesarean section demands. RESULTS AND CONCLUSIONS: Incorrect knowledge of delivery, fear of delivery pain, lack of vaginal delivery confidence and doctors' talk with pregnant women about risks of delivery have significantly different (P < 0.05) influences on the two groups. Those are the four important factors of women's cesarean section demands.

Anxiety↗
PubMed2000

[Expression of transforming growth factor-beta 1 mRNA and osteopontin mRNA in UMR-106 cells under mechanical stimulation].

OBJECTIVE: To investigate the effects of the mechanical stretching on the expression of osteopontin (OPN) mRNA and transforming growth factor-beta 1 (TGF beta 1) mRNA in a rat osteosarcoma cell line (UMR-106), and to unveil the cellular mechanism of mechanical force-induced bone remodeling. METHODS: An apparatus was designed and fabricated by which force was loaded onto the cultured cells in vitro. Digoxin-labeled cDNA probes were used for in situ hybridization in combination with image analysis technique to relatively quantify the intensities of the hybridization signals. RESULTS: Various magnitudes and durations of the mechanical stretching did exert different influences on the intensities of the mRNAs' expression. Of all the combinations, the low tension/frequency group showed the most remarkable alteration of TGF-beta 1, as increased from 0.0899 to 0.1756 (P < 0.01). Some putative relations lay between the expressions of the OPN mRNA and the TGF-beta 1 mRNA. CONCLUSION: The mechanical stretching can inevitably influence the expression of OPN mRNA and TGF-beta 1 mRNA. The beneficial alteration obtained in using low tension/frequency action mode suggests and verifies the use of relatively constant and light force to move teeth in clinical orthodontics.

Animals↗
PubMed2000

[Genes of micrometastasis in bone marrow of patients with colorectal cancer].

OBJECTIVE: To detect the gene of micrometastasis in bone marrow of patients with colorectal cancer. METHODS: PCR-SSCP/silver stain technique was used to find out the metastatic cancer cells in 51 bone marrow samples in different time. RESULTS: The total positive rate of mutations of p53 and K-ras in bone marrow was 37.25% before operation. The incidence of mutations was obviously correlated with Duke's stage and lymphatic metastasis. After postoperative chemotherapy mutation in 11 patients turned to be negative. CONCLUSIONS: Detection of micrometastasis in bone marrow may contribute to early diagnosis of blood stream metastasis of colorectal cancer.

Bone Marrow Neoplasms↗
PubMed2000

[Expression and significance of AR in osteosarcoma].

OBJECTIVES: To determine the relationship between AR and pathological characteristics of osteosarcoma and to investigate the potential role of AR in the pathogenesis of osteosarcoma. METHODS: AR in the samples of the paraffin embedded tissues from 65 cases of osteosarcoma was immunohistochemically detected by streptavidin/peroxidase (SP) method. The pathology of osteosarcoma was classified and graded according to Liu Zijun's Classification. RESULTS: The positive rate of AR was 50.8% (33/65). The positive particles were distributed in the cytoplasm and nucleus. The positive rate of AR in osteosarcoma with higher grade of cell differentiation was lower than that in the tumor with lower one. There was no significant difference in different pathological type of osteosarcoma. CONCLUSION: AR exists in osteosarcoma and its positive rate is related to the cell differentiation of osteosarcoma.

Bone Neoplasms↗