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Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 469 records · Page 26Linked to original sources
PubMed2000

[Yi nationality's sacred groves and biodiversity conservation in Chuxiong, Yunnan].

Sacred groves occur in many ethnic minority areas of Yunnan, China, which have ecologically multiplex functions and effects on biodiversity management and conservation at grassroots level. In this paper, an extensive field survey was carried out to evaluate the role of the sacred groves of the Yi nationality in Chuxiong of Yunnan. Three forest communities (sacred grove, common forest and natural reserve) under different management were sampled, and their plant species diversity was compared. The result shows that the total species, endemic species and Shannon-Wiener index in the sacred grove community were respectively 67, 17 and 2.96, higher than those in natural reserve (44.8 and 2.17) and common forest (34.4 and 2.39). The sacred groves of the Yi nationality in Chuxiong of Yunnan play an important role in local biodiversity conservation and management.

Ecosystem↗
PubMed2000

The relationship between Th1/Th2-type cells and disease activity in patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the imbalance of Th1/Th2-type cytokines in patients with systemic lupus erythematosus (SLE) and its relation to disease activity. METHODS: Intracellular cytokines were determined by flow-cytometry following whole-blood culture. RESULTS: Patients with systemic lupus erythematosus disease activity index (SLEDAI) > 10 had statistically significantly fewer CD4+ or CD8+ T cells producing IFN-gamma than patients with SLEDAI = 0, SLEDAI 1-10 or healthy controls (P < 0.01, P < 0.01 or P < 0.05, respectively). Patients with SLEDAI > 10 also had decreased ratio of IFN-gamma/IL-4 positive CD4+ or CD8+ T cells, compared with patients with SLEDAI = 0, SLEDAI 1-10 or healthy controls (P < 0.05). The decreased Th1 or Tc1 cells and the ratios of IFN-gamma: IL-4 positive CD4+ T-cells were significantly correlated with disease activity (P < 0.05). CONCLUSION: SLE is characterized by an imbalance of Th1/Th2 and Tc1/Tc2 cytokines. The decreased Th1 or Tc1 cells and the Th1/Th2 ratio are related to disease activity.

Adult↗
PubMed2000

Impact of RT-PCR monitoring on the long-term survival in acute promyelocytic leukemia.

OBJECTIVE: To evaluate the impact of kinetics of molecular remission via retro-transcriptase polymerase chain reaction (RT-PCR) assay on the long-term survival in patients with acute promyelocytic leukemia (APL). METHODS: Seventy patients with newly-diagnosed APL in remission were involved in this study. Monitoring of minimal residual disease (MRD) was performed regularly by RT-PCR assay for PML-RAR alpha during consolidation. RESULTS: A 5-year relapse-free survival (RFS) and overall-survival (OS) were estimated as 46.8% +/- 8.4% and 69.9% +/- 9.4% for the whole group. Fifty-two (74.3%) patients got negative RT-PCR result at least once. Serial monitoring of RT-PCR was available in 38 cases and 24 (63.2%) patients presented with persistent negative PCR results. The achievement and continuous negative RT-PCR result was significantly related to the RFS. CONCLUSIONS: Achievement of negative RT-PCR in remission is associated with favorable RFS and OS. Continuous negative RT-PCR results are associated with long-term relapse-free survival and may be considered as potentially curative. RT-PCR assay for detection of MRD should be performed regularly during post-remission period as an important prognostic factor.

Adolescent↗
PubMed2000

Noninvasive three-dimensional computed tomographic angiography in preoperative detection of intracranial arteriovenous malformations.

OBJECTIVE: To assess the value of noninvasive three-dimensional computed tomographic angiography (3D-CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs). METHODS: A prospective evaluation at a single institute over a 2-year period included 23 patients suspected of intracranial AVMs. All patients underwent 3D-CTA and digital subtraction angiography (DSA). Results from both procedures were compared. RESULTS: 3D-CTA imaging provided excellent visualization of intracranial AVMs. The false positive error and false negative error were zero in our sample. The details of arterial supply (numerical measure, orientation, caliber and routing) and vascular nidus (size, morphosis and location) provided by 3D-CTA images were the same as DSA and the details of venous drainage were an approximate match. Additionally, 3D-CTA can depict tridimensional anatomical information for AVMs and their relationship to adjacent structures, a function not possible with DSA. This assisted the surgeons in making better surgical planning and reduced trauma. As a noninvasive course, there were no related-complications in the course of 3D-CTA processing. CONCLUSIONS: DSA is still regarded as the gold standard for intracranial AVMs detection. The modality of 3D-CTA is accurate, noninvasive, nearly risk free and low-price; we could routinely use it instead of or as a supplement to DSA, in the preoperative detection of suspected intracranial AVMs and postoperative radiological follow-up. 3D-CTA adds tridimensional aspect and assists the surgeon in a the more accurate therapeutic scheme. Preliminary data suggest that 3D-CTA is playing a favorable role in the assessment of patients with intracranial AVMs.

Adolescent↗
PubMed2000

[Expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 protein in the implantation window phase of endometrium].

OBJECTIVE: To study the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-3 (TIMP-3) protein in the implantation window phase of endometrium and the role of MMP-9 and TIMP-3 on embryo implantation. METHOD: Immunohistochemical analysis was employed to demonstrate the population of the MMP-9 and TIMP-3 positive cell in endometrium of different phases of menstrual cycle. RESULTS: The positive cells of these soluble proteinases were found to be located in the endometrial epithelial cells and stromal cells. The quantitative analysis of MMP-9 and TIMP-3 proteins demonstrated an increase in staining exent from proliferative endometrium to the endometrium of implatation window phase, and an decrease to late-secretory endometrium in comparison with the implantation window phase. CONCLUSION: Expression of MMP-9 and TIMP-3 in the implantation window phases of endometrium is specific and may play an important role in regulating the depth of trophoblast invasion during embryo implantation and may be involved in endometrial stromal breakdown during menstruation.

Adult↗
PubMed2000

Hyperbaric oxygen preconditioning induces neuroprotection against ischemia in transient not permanent middle cerebral artery occlusion rat model.

OBJECTIVE: This study was designed to determine if repeated hyperbaric oxygen (HBO) exposure induces ischemic tolerance in focal cerebral ischemia. METHODS: Sixty male SD rats were used in this study. Thirty animals underwent transient middle cerebral artery occlusion (MCAO) and the other thirty permanent MCAO model. The rats were randomly allocated to 3 sub-groups: control group (n = 10), HBO-3 group (n = 10), and HBO-5 group (n = 10). The animals in HBO-3 and HBO-5 groups received 1 hour hyperbaric oxygenation at 2.5 atmosphere absolute (ATA) in 100% oxygen every day for 3 and 5 days, respectively. The animals in the control group received sham treatments. 24 hours after the last HBO, transient MCAO (120 min) and permanent MCAO were induced by introducing a 3-0 nylon monofilament suture through internal carotid artery based on the Koizumi technique. The neurological outcome was evaluated until 24 hours after reperfusion in transient MCAO rats and ischemia in permanent MCAO rats. The infarct volume was then assessed by TTC staining. RESULTS: In transient MCAO rats, the neurological outcome in both the HBO-3 and HBO-5 groups was better than that of the control group (P < 0.05 and 0.001). The infarct volume decreased from 171.5 +/- 113 mm3 to 40.6 +/- 49.9 mm3(P < 0.05) in the HBO-3 group and 16.2 +/- 28.8 mm3(P < 0.01) in the HBO-5 group. There were no significant differences in neurological outcome and infarct volume among the three groups in permanent MCAO rats. CONCLUSIONS: The present study demonstrated that HBO preconditioning can induce ischemic tolerance in transient not permanent MCAO rats in a "dose-dependent" manner.

Animals↗
PubMed2000

An investigation of immunocompetence substances in normal gingival and periodontitis tissue.

OBJECTIVE: To investigate the effects of nitric oxide (NO), endothelin (ET), substance P (SP) and calcitonin gene-related peptide (CGRP) immunocompetence substances and their relationship to chronic periodontitis. METHODS: Immunohistochemical aod histochemical staining methods were used to detect the expression of the NO synthase (NOS), ET, SP and CGRP levels in 20 patients with chronic periodontitis and 20 healthy subjects as control. RESULTS: Quantitative analysis by Quantimat 970 showed that NOS and ET in periodontitis tissue increased significantly (P < 0.01), particularly the content of ET in comparison with healthy subjects. The intergroup expression of SP and CGRP showed no remarkable changes. CONCLUSION: Our results demonstrate that the level of NOS and ET were significantly increased in periodontic tissue, which may diminish the blood supply and influence the periodontal tissue causing tissue damage. Our study suggests that immunocompetence substances NO and ET are closely associated with periodontitis and may play an important role in the disease.

Adult↗
PubMed2000

99mTc-MIBI and 99mTc-MDP scintimammography for detecting breast carcinoma.

OBJECTIVE: To assess the value of scintimammography with both 99mTc-MIBI and 99mTc-MDP in detecting breast cancer. METHODS: A total of 35 women with clinical findings of suspicious breast lesions were studied with both 99mTc-MIBI and 99mTc-MDP scintimammography. All patients underwent surgery within one week and the final diagnostic results (histopathological) were obtained. RESULTS: Eighteen of 35 abnormalities of breast were pathologically confirmed as breast cancer and 17 as benigN lesions. In this group of patients studied, the sensitivity, specificity and accuracy of 99mTc-MIBI scintimammography were 77.8%, 88.2% and 82.9%, respectively and those of 99mTc-MDP scintimammography were 72.2%, 88.2% and 80.0%, respectively. There was no significant difference between 99mTc-MIBI and 99mTc-MDP scintimammography. CONCLUSION: This study showed the high diagnostic accuracy of both 99mTc-MIBI and 99mTc-MDP scintimammography in detecting breast cancer. Both can be used as non-invasively assess breast cancer invasiveness before surgery.

Adult↗
PubMed2000

[Expression of epidermal growth factor receptor in human preimplantation embroys].

OBJECTIVE: To investigate the expression of epidermal growth factor receptor (EGFR) in human preimplantation embryos and to explore the effect of EGFR on human embryos growth, development and implantation. METHODS: To detect the localization and expression of EGFR in human preimplantation embryos with indirect immunofluorescence assays(IIF). RESULTS: There was EGFR expression in human preimplantation embryos from unfertilized oocyts, 2-cell, 4-cell, 6-8 cell to 10-cell stages embryos. EGFR protein located on the cell membrance surface, and had no obvious variation in intensity of staining from whole stages embryos. CONCLUSION: The expression of EGFR was present in human preimplantation embryos, heparin-binding EGF-like epidermal growth factor (HB-EGF), one of the EGF superfamily members act through the EGFR, EGFR expression may have an important role in human embryos growth, development and implantation.

Blastocyst↗
PubMed2000

[The influence of malocclusion on self-esteem and personality of college student].

OBJECTIVE: To study the relationship among the different malocclusions and self-esteem and personality. METHODS: Two hundred and forty college students with normal occlusion and different types of malocclusion were classified into four groups(class I, class II, class III and normal) by Angle's classification, Sixty students in each group. The first three groups had been divided into three subgroups respectively by IOTN: mild, moderate and severe, twenty students in each subgroup. Each subject was assessed by using the body-esteem scale (BES) and the Eysenck personality questionnaire (EPQ). RESULTS: (1) the mean score on facial appearance subscale in BES of the normal group is significantly higher than that of moderate and severe subgroups in class II and class III groups; (2) the mean T score on E subscale in EPQ of the normal group is significantly higher than that of severe subgroups in class II and class III groups, and the mean T score on N subscale in EPQ of the normal group is significantly lower than that of severe subgroups in class II and class III groups; (3) There is a positive correlation between the mean score on facial appearance subscale in BES and the mean T score on E subscale in EPQ and a negative correlation between the mean score on facial appearance subscale in BES and the mean T score on N subscale in EPQ. CONCLUSIONS: (1) The students with moderate and severe class II and class III malocclusion have lower self esteem about their facial appearance than normal students; (2) The trends of introverstion and astatic emotion are higher in students with severe class II and class III malocclusion than in normal students; (3) The higher self esteem about his (or her) facial appearance, the higher trends of extroversion and statical emotion he(or she) has; the lower self-esteem about his (or her) facial appearance, the higher trends of introversion and astatic emotion he (or she) has.

Adult↗
PubMed2000

[Clinical understanding and therapeutic analysis of multiloop edgewise archwire correction of Angle Class II malocclusion].

OBJECTIVE: To use multiloop edgewise archwire (MEAW) to correct class II malocclusion and to analyse its therapeutic effects and principles. METHODS: 10 class II division 1 and 3 class II division 2 cases were treated with MEAW technique. RESULTS: Gratifying results have been achieved in all cases in a relatively short period of time. CONCLUSIONS: With full understanding of correcting principle of the archwire for class II malocclusion and active cooperation of the patient, the MEAW technique produces twice the result with half the effort.

Adolescent↗
PubMed2000

[Effect of protein expression on antisense c-myc and PCNA for vascular smooth muscle cells].

OBJECTIVE: To study the methods of inhibiting proliferation of vascular smooth muscle cells (VSMCs), we observed the change of protein expression after using antisense c-myc, PCNA for VSMCs. METHODS: The sense, antisense, and mismatched oligomers for c-myc or PCNA were individually delivered to the cultured VSMCs. Using Western blot, immunohistochemistry assay and image analysis system, we observed the change of c-myc and PCNA protein expression in the VSMCs. RESULTS: Antisense c-myc, PCNA at concentration of 10 micromol/L can successfully inhibit the expression of c-myc, PCNA protein in the VSMCs (P < 0.05), but the sense and the mismatched do not have this effect (P > 0.05). CONCLUSION: The data suggested that the antisense c-myc, PCNA could attenuate the protein expression of c-myc, PCNA, and it is an effective method for the inhibition of VSMCs hyperplasia.

Blotting, Western↗
PubMed2000

[Ultrastructural study on the peripheral nerve and skeletal muscle of patients with spastic cerebral palsy].

OBJECTIVE: To explore pathological features of the peripheral nerve and skeletal muscle of patients with spastic cerebral palsy. METHODS: The peripheral nerve and skeletal muscle of 25 patients with spastic cerebral palsy were observed by gross examination during operation, and under microscope and electron microscope. RESULTS: Gross examination showed that peripheral nerve and skeletal muscle was normal during operation. Microscope showed that some skeletal muscle fibers degenerated, and the connective tissue proliferated. electronmicroscopically the damage of demyelination was extensive on the peripheral nerve; the pathological changes of Schwann's cell were sooner and more severe than axons; the pathological changes of myelinated nerve fiber were more obvious than the nonmyelinated nerve fiber; the lymphocyte were found around the microvasculature within the perineurium; the mitochondrion of skeletal muscle fiber increased in number, the sarcoplasmic reticulum and transverse tubule decreased and developed badly, the degenerative muscle fiber showed cell edema or the pathological changes of myofibril. All the peripheral nerve and skeletal muscle fiber affected had no repair and regeneration. CONCLUSIONS: The demyelination of the peripheral nerve of patients with spastic cerebral palsy is primary, and the skeletal muscle of patients with spastic cerebral palsy is secondary pathological change. The activity of nerve and muscle regeneration is bad.

Adolescent↗
PubMed2000

[A 1:2 matched case-control study on the risk factors of uterine myomas].

OBJECTIVE: To investigate the risk factors and their association with Uterine myomas. METHODS: A 1:2 matched case-control study was carried out in Guangzhou including 211 cases and 422 controls. Data were analyzed with conditional logistic regression. RESULTS: Results showed that Pelvic inflammatory, Erosion of Cervix, Menopathy, Adnexitis and family history of Uterine myomas were identified as risk factors, with odds ratios of 3.101, 2.904, 3.942, 7.742 and 2.426 respectively while delayed menstruation was proved to be a preventive factor, with odds ratios of 0.841. CONCLUSION: Uterine myomas seemed to be related to Pelvic inflammatory, Erosion of Cervix, Adnexitis, Menopathy and family history of Uterine myomas.

Adult↗
PubMed2000

[Hostility behavior as risk factor of coronary heart disease].

OBJECTIVE: To explore the relationships between hostility, and the risks of coronary-prone behavior and the clusters of unhealthy behaviors in individuals with different levels of hostility. METHODS: A cross-sectional study was carried out among 1 010 male employees from two factories in Beijing Capital Steel and Iron Company in 1997. Data on major risks of cardiovascular, other social-demographic factors and levels of hostility by Cook-Medley Scales were collected. RESULTS: Body mass index, amounts of cigarette smoking and alcohol drinking were significantly increased (P < 0.01) with a characteristic of reduced social support from one's colleagues, when individual's level of hostility increased. In addition, less years of education, higher prevalence of other chronic diseases (P < 0.05) and clustering of various unhealthy behaviors were found related to the increase of individual's hostility. The odds ratio in the group with highest hostility was 2.37 times higher than in the lowest one, after confounding effects from age, blood pressure, education level, status of chronic disease and social support being adjusted. No significant differences on both systolic and diastolic blood pressures among groups with different levels of hostility were discovered. CONCLUSION: The association between hostility, coronary-prone risk behavior and cluster of unhealthy behaviors suggested that hostility might increase the risk of coronary heart diseases through affecting individual's behavior.

Adolescent↗
PubMed2000

[Analysis for the titer of plasma antibody to heat stress protein 70 in workers exposed to benzene].

OBJECTIVE: To explore the titer of plasma antibody against heat stress protein 70 (HSP70) in workers exposed to benzene and its possible relationship to their health. METHODS: Forty-two workers exposed to more than 40 mg/m(3) of benzene were selected as a high exposure group, 50 of workers exposed to less than 40 mg/m(3) as a low exposure group, and 42 unexposed as a control group. Their plasma antibody against HSP70 was determined with enzyme-linked immunosorbent assay (ELISA). Analysis was conducted to study the relationship between it and other factors. RESULTS: Proportion of plasma positive antibody to HSP70 with a titer of 1:20 was significantly higher in high exposure group (26.2%) than that in controls (9.5%). Moreover, prevalence of adverse symptoms and positive signs, and level of lipid peroxide were all significantly higher in high exposure group with positive antibody to HSP70 than those with negative antibody. CONCLUSION: It was concluded that the titer of plasma antibody to HSP70 had close relation with the health of workers exposed to benzene.

Adult↗
PubMed2000

[A study on relationship between plasma heat stress protein 70 and cytokine in patients with heat apoplexy].

OBJECTIVE: To study the change of levels of plasma heat stress protein 70 (HSP70) and cytokine and their interrelationship in pathogenicity of heat apoplexy. METHODS: Plasma HSP70 was determined with Western blot, and plasma interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R) and interleukin-6 (IL-6) were determined with enzyme-linked immunosorbent assay (ELISA). RESULTS: Plasma level of HSP70 was 4 211.2 +/- 1,286.2 (integral optical density) in average in the patients of heat apoplexy group, 4,137.8 +/- 1, 207.5 in those of severe heat apoplexy group, and 6,043.5 +/- 1,354.8 in control group, with very significant difference (P < 0.01). Plasma IL-2 level was (64.3 +/- 32.3) pg/ml and (200.0 +/- 50.0) pg/ml and sIL-2R (54.9 +/- 33.3) U/ml and (167.5 +/- 89.0) U/ml in the patients with heat apoplexy and in controls, respectively, with very significant difference. But, there was no significant difference in IL-6 between varied groups. CONCLUSIONS: The above-mentioned results suggest that establishment of heat acclimatization correlates to the interaction of network of neuroendocrine-cytokine-HSP, in which decrease in plasma IL-2 was one of the important factors causing reduction of HSP70 expression. Balance of network regulation was broken by pathological factors, finally resulting in heat apoplexy.

Adolescent↗