Biomedical subjects

J Yang

Publications and source records attributed to J Yang.

At least 523 records · Page 29Linked to original sources

PubMed2000

[Sequence analysis of the 5' and 3' terminal regions of dengue type 2 virus 04 strain].

OBJECTIVE: To analyze the sequences of 5' and 3' terminal region of dengue type 2 virus 04 strain. METHODS: Total RNA was isolated from dengue type 2 virus 04 strain (D2-04) infected C6/36 cells. With this RNA as template, the cDNA of both 5' and 3' termini of D2-04 were amplified using RACE method respectively. The cDNAs were separately inserted into pGEM-T vector and the recombinant plasmids containing the 5' terminus 535 bp and 3' terminus 503 bp were obtained. The nucleotide sequences of the inserted cDNA fragment were determined. The nucleotide sequences of the 5' and 3' noncoding regions of D2-04 were compared with other dengue type 2 viruses such as JAM, NGC, S1, 16681 and PD-53. RESULTS: The results showed that they shared 98.96%, 98.96%, 93.75%, 98.95%, 97.92% and 97.72%, 97.80%, 90.65%, 94.26%, 94.22% homology with D2-04 strain respectively. CONCLUSIONS: Except SI, the homology between D2-04 and other type 2 viruses was higher than 94%.

Base Sequence↗

PubMed2000

[Comparison analysis between potential and actual pattern of artificial oases in arid region].

Based on theoretical analysis and demonstration research, the conception of potential pattern in the agriculture landscape of artificial oases in Xinjiang arid region and its analysis unit were discussed. The potential landscape pattern was defined as the one composed by spatial units with basic characteristics and properties which had no change or less change with the time. In agriculture landscape, soil was found to be a relatively stable element, and hence, different soil classification unit could be used to analyze the potential landscape pattern. A case study was carried out to analyze the potential and actual pattern of the artificial cases in Shihezi reclamation area by using the indexes of diversity, evenness, aggregation, mean patch elongation, patch shape fragmentation and mean patch fractal dimension. The result showed that the landscape pattern changed orderly from the potential to actual pattern, and the potential pattern could be used as the absolute criterion for researches on pattern changes in agriculture landscape.

Agriculture↗

PubMed2000

[A primary study on distribution and binding forms of arsenic in polluted crop seeds].

The distribution, binding form and processing removal of arsenic in rice and wheat seeds were studied. The result shows that the distribution of arsenic in seed parts was uneven, as concentration in rice seed was embryo > seed capsule > chaff > endosperm, and that in wheat seed was embryo > seed capsule > endosperm. Arsenic was mainly accumulated in endosperm, and mainly in the form of protein-binding. With the removal of chaff, coarse rice bran and fine rice bran in the processing, the content of arsenic decreased by 16.51%, 12.41% and 10.26%, respectively. Similarly, with the removal of coarse wheat bran and fine wheat bran, it decreased by 22.0% and 45.6%, respectively.

Arsenic↗

PubMed2000

Alternation of Na(+)-Ca2+ exchange in rat cardiac sarcolemmal membranes during different phases of sepsis.

OBJECTIVE: To study the alteration of Na(+)-Ca2+ exchange in rat cardiac sarcolemmal membrane during phases of septic shock. METHODS: Sepsis was induced by cecal ligation and puncture (CLP). Na(+)-Ca2+ exchange was assayed by radioactive analysis. RESULTS: Na(+)-dependent 45Ca2+ uptake was decreased by 62%-69% in late phase of sepsis, whereas it was not affected in early phase of sepsis. Na(+)-Ca2+ exchange stimulated by 5' guanylyl imidodiphosphate [Gpp (NH) p] was decreased by 65.7% in late phase of sepsis but unaltered in early phase of sepsis. Two agonists (angiotensin II and phenylephrine) coupled to Gq and a protein kinase C activator, phorbol 12-myristate 13-acetate (PMA) all inhibited Na(+)-Ca2+ exchange in late phase of sepsis. Na(+)-Ca2+ exchange activities induced by phosphorylation of Na(+)-Ca2+ exchange were decreased in late phase of sepsis, whereas inhibition of Na(+)-Ca2+ exchange by dephosphorylation was increased both in early and late phases of sepsis. CONCLUSION: The alteration of Na(+)-Ca2+ exchange during different phases of sepsis might be related to the activities of Gq, protein kinase C, and phosphorylation/dephosphorylation.

Animals↗

PubMed2000

Pulmonary embolism associated with nephrotic syndrome in children: a preliminary report of 8 cases.

OBJECTIVE: To investigate the incidence, clinical features of pulmonary embolism (PE) secondary to nephrotic syndrome(NS) in Chinese children. METHODS: Pulmonary perfusion imaging (PPI) and chest radiography was performed on 20 NS patients with elevated plasma D-dimer. The patients with PE were given anticoagulative therapy with heparin and persantine. RESULTS: Among 20 NS patients, eight cases, aged from 5 to 12 years, 6 boys and 2 girls, were found to have PE. Of them 5 were primary NS and 3 were secondary NS. PPI showed an involvement of 1 pulmonary segment in 3 cases, of 2 pulmonary segments in 2, of 3 pulmonary segments in 2, and of 6 pulmonary segments in 1. Most patients did not present clinical signs and symptoms. Two weeks after the administration of intravenous heparin for anticoagulative therapy, 6 out of 8 cases showed a recovery or an improvement. CONCLUSION: The results of this study suggest that PE be not a rare complication in NS children. Most patients had no obvious clinical manifestation and their prognose was favorable if diagnosed and treated in time.

Adolescent↗

PubMed2000

Interventional treatment of huge hepatic cavernous hemangioma.

OBJECTIVE: To study the methods of interventional treatment of huge hepatic cavernous hemangioma (HCH). METHOD: A total of 14 patients with HCH were treated with lipiodol-ultrafluid (10-15 ml), bleomycin A (PYM 16-32 mg), and gelatin-sponge particles. RESULTS: DSA hepatic arteriography showed multiple vascular lakes in the early arterial phase, so-called "to hang the fruits on the branches", which persisted for a long time. CT scan showed a significant reduction in tumor size in 8 of the 14 patients after the treatment. CONCLUSION: Embolization with lipiodol-ultrafluid, PYM and gelatin sponge particles is one of the best methods for the treatment of HCH.

Adult↗

PubMed2000

[Endothelial dysfunction and injury of placental and umbilical vessels in pregnancy-induced hypertension is associated with tumor necrosis factor].

OBJECTIVE: To investigate the relation between endothelial dysfunction and injury of placental and umbilical vessels in pregnancy-induced hypertension (PIH) and tumor necrosis factor (TNF). METHODS: The concentration of plasma TNF, endothelin (ET) and nitric oxide (NO) in PIH women and normal pregnant women (control group) were measured. The ultrastructure of placenta and umbilical vein endothelial cells in PIH and normal pregnant women was observed. The ultrastructure of endothelial cells in culture with TNF (400 u/ml) was also observed. RESULTS: Maternal plasma TNF and ET levels in PIH patients were (2.27 +/- 0.42) micrograms/L and (73.31 +/- 9.98) ng/L, respectively, higher than that in the control [TNF and ET lever were (1.72 +/- 0.25) micrograms/L and (2.32 +/- 10.44) ng/L, respectively]. NO level in PIH patients was (104.93 +/- 20.54) mumol/L, lower than that in the control [NO lever was (138.25 +/- 22.16) mumol/L] (P < 0.05). The ultrastructure of placental and umbilical vascular endothelial cells in moderate and severe PIH patients revealed injured. Similar injury was observed in endothelial cells in culture with TNF. CONCLUSIONS: TNF can induce the endothelial cells dysfunction and injury. It may be involved the pathogenesis of PIH.

Adult↗

PubMed2000

[Study on left ventricular function of chronic obstructive pulmonary diseases in stable phase by using nuclear techniques].

OBJECTIVE: To study the left ventricular function of chronic obstructive pulmonary diseases in stable phase. METHOD: The systolic and diastolic function of the left ventricles of chronic obstructive pulmonary diseases was studied by using gate cardiac blood-pool imaging. RESULTS: There are no statistical significance in left cardiac systolic and diastolic function of the patients with different degrees of chronic obstructive pulmonary diseases and control group of normal lung function on left ventricle ejection fraction(LVEF), peak ejection rate(PER), ejection fraction at one third of TES from end-diastole(1/3EF), ejection fraction rate at one third of TES from end-diastole(1/3ER), time between end-diastole and end-systole(TES), time to peak filling from diastolic to end-systole(TPE), peak filling rate(PFR), filling fraction at 1/3(TES) from end-systole(1/3FF), filling rate at 1/3 (TES) from end-systole(1/3FR). CONCLUSION: There is no significant difference in left ventricular function in patients with different degrees of chronic obstructive pulmonary diseases in the stable phase.

Adult↗

PubMed2000

[Assessment of treatment regimens in 58 cases with acute pulmonary embolism].

OBJECTIVE: To explore the best regimen of treatment for acute pulmonary embolism(APE), and to evaluate the efficacy and safety of 2-h infusion of recombinant tissue-type plasminogen activator, Alteplase (rt-PA) and urokinase(UK). METHODS: Fifty-eight patients with APE diagnosed by perfusion lung scanning (ECT) or angiography(CPA) were treated with different regimens: i.e. 2-h infusion of rt-PA or UK (2-h group); low doses of UK for 3-7 days (Qd group); anticoagulants alone and thromboectomy. The results were compared. RESULTS: Of the 41 patients treated with thrombolytic therapy 78% showed improvement in lung perfusion scan and clinical presentation without severe adverse effects, the percentage was significantly higher than that of the anticoagulant group(P < 0.001). The rate of improvement was 84% if thrombolytic therapy was given in 2 h. The mortality rate was lower than anticoagulants and thromboectomy group. The success rate of thromboectomy was 40%. CONCLUSIONS: A 2 h regimen of rt-PA or UK showed reliable efficacy and safety for treatment of APE. The indication of thrombolytic therapy can be extended. Mortality and morbidity could be reduced if thrombolytic therapy followed by anticoagulation is applied as early as possible.

Acute Disease↗

PubMed2000

[Clinical significance of ProGRP31-98 in patients with small-cell lung cancer].

OBJECTIVE: To determine the clinical significance of serum level of pro-gastrin-releasing peptide 31-98 (ProGRP31-98) for small-cell lung cancer (SCLC) in comparison with neuron-specific enolase (NSE). METHODS: Serum level of ProGRP31-98 was measured by ELISa in 30 patients with SCLC, 30 patients with non-small-cell lung cancer (NSCLC), 10 patients with SCLC who had received treatment, 15 patients with benign lung diseases and 15 normal subjects. The receiver operating characteristic (ROC) curve was used to set the cut-off value and evaluate the diagnostic accuracy. RESULTS: The serum level of ProGRP31-98 was significantly increased in patients with SCLC as compared to that of the normal controls as well as that in any other groups of patients. It was higher in SCLC patients with extensive disease than in patients with limited disease. In patients with distant metastases, it was also higher than in those without. Increase in serum ProGRP31-98 and NSE was both seen in SCLC patients, but the former was of much greater magnitude when compared to the normal controls. Given the cut-off levels of 40 pg/ml for ProGRP31-98 and 8 micrograms/L for NSE, their sensitivity of diagnosis in SCLC was 73% and 60%, respectively. The area under ROC curve of ProGRP31-98 was significantly larger than that of NSE. Similar results of diagnostic sensitivity and area under ROC curve were observed in SCLC patients with limited disease. All patients responded to chemotherapy showed marked decrease in ProGRP31-98. CONCLUSION: ProGRP31-98 is a more specific and sensitive marker than NSE for the diagnosis of SCLC.

Adult↗

PubMed2000

[The clinical significance of true insulin and proinsulin levels in subjects with different glucose tolerance].

OBJECTIVE: To examine the levels of serum true insulin (TI) and proinsulin (PI) in individuals with different glucose tolerance and to assess its clinical significance. METHODS: The levels of true insulin and proinsulin during oral glucose tolerance test (OGTT) were determined with specific BA-ELISA in 135 normal glucose tolerance (NGT) and 86 impaired glucose tolerance (IGT) subjects as well as 101 type II diabetes mellitus (DM) patients. RESULTS: The fasting TI levels showed no significant difference (P > 0.05) among the groups of NGT, IGT and type II DM, but the immunoreactive insulin (IRI) concentration increased significantly in type II DM patients as compared with that in NGT (P < 0.01). Both of the fasting PI levels and the ratio of PI/(PI + TI) were significantly higher in type II DM patients as compared with those in NGT or IGT. The area under the curve of TI (AUC(TI)) was significantly higher (P < 0.05) in IGT than NGT and type II DM. Obese subjects had higher TI levels (P < 0.01) and lower insulin sensitivity (P < 0.05) than those in non-obese, while the ratio of PI/(PI + TI) and AUC(TI) was not significantly different statistically (P > 0.05) between the obese and non-obese subjects. CONCLUSION: Type II DM patients present hyperproinsulinemia rather than hyperinsulinemia and have higher ratio of PI/(PI + TI) as compared with NGT and IGT subjects. Higher TI level and significant insulin resistance were observed in obese subjects, but there is no difference of the PI/(PI + TI) ratio. The fasting PI level and PI/(PI + TI) ratio tend to be the indexes of beta-cell dysfunction.

Adult↗

PubMed2000

[Role of tumor necrosis factor -alpha in the pathogenesis of pregnancy-induced hypertension].

OBJECTIVE: To investigate the role of tumor necrosis factor-alpha (TNFalpha) in the pathogenesis of pregnancy induced hypertension (PIH) by damaging endothelial cells. METHODS: 41 patients with PIH and 17 healthy pregnant women were studied. The concentration of TNFalpha in maternal plasma was measured by sensitive radioimmunoassay. The morphology of endothelial cells of placental blood vessels was observed. Endothelial cells were incubated in the presence of TNFalpha (400 U/ml) and sera (30% vol/vol) from PIH women and normal pregnant women to observe their growth and shape. RESULTS: Maternal plasma TNFalpha level in PIH was 2.29 microgram/L +/- 0.51 microgram/L, higher than that in normal pregnancy (the latter was 1.73 microgram/L +/- 0.25 microgram/L, t = 5.60, P < 0.01). The endothelial cells of placental blood vessels in PIH revealed morphologic damages. Both sera of PIH women and TNFalpha were cytotoxic to endothelial cells in culture, including inhibition of the proliferation and morphologic changes of the cells. CONCLUSION: Damage of the endothelial cells of placental blood vessels is associated with the abnormal increase in the maternal blood TNFalpha. Sera of PIH women can damage the endothelial cells in culture and this effect is also associated with TNFalpha.

Adult↗

PubMed2000

[Clinical application of magnetic resonance angiography in the body].

OBJECTIVE: To identify the accuracy and reliability of magnetic resonance angiography (MRA) in evaluating patients with vascular lesions in the body. METHODS: 171 patients with suspected vascular lesions in the body were examined by MRA and compared with the results of X-ray angiography (XRA) or operation. RESULTS: MRA showed abnormal vein in 12 patients and normal in 6 corresponding to XRA or operation. MRA revealed aneurysm in 54 patients: aortic dissection (26), aortic aneurysm (15) and peripheral aneurysm (13). Two peripheral aneurysms could not only be found by MRA. The sensitivity of MRA was 97% for aneurysm lesions. The sensitivity of MRA in the diagnosis of suspicious peripheral artery stenosis in 84 patients was 95%, the specificity 89%, and the accuracy 92% in comparison with those of XRA and operation. CONCLUSION: MRA is accurate and reliable in evaluating vascular lesion in the body and can replace XRA in many cases.

Adolescent↗

PubMed2000

[Penetrating wounds of the heart: analysis of 56 patients].

OBJECTIVE: To assess the management of penetrating cardiac injuries. METHODS: 56 patients with penetrating wounds of the heart were studied retrospectively. The study lasted for 11 years. RESULTS: Stab wounds accounted for 89.3% of the 56 patients. 56 patients underwent thoracotomy. Preoperative infusion was less than 1,000 ml in 68% of the patients. Preoperative pericardiocentesis was done only in 2 patients, of whom one was false negative. Four patients with cardiac arrest soon after arrival were subjected to emergency thoracotomy; three survived. After the operation, 2 patients died of associated abdominal injuries and failure of cerebral resuscitation. The overall survival rate was 96.4%. CONCLUSIONS: Early diagnosis and prompt thoracotomy are essential to the treatment of penetrating cardiac injuries. Preoperative massive transfusion and pericardiocentesis are not advocated.

Adolescent↗

PubMed2000

[Anterior segment reconstruction and secondary posterior chamber intraocular lens implantation supported by fibromembrane].

OBJECTIVE: To evaluate the methods and effects of anterior segment reconstruction and secondary posterior chamber intraocular lens (IOL) implantation supported by fibromembrane in pupillary area. METHODS: Anterior segment was reconstructed in 86 eyes with different anterior segment disorders. Anterior segment reconstruction includes: partial penetrating keratoplasty, loosing front adhesion, suturing detached peripheral iris, loosing rear adhesion, reshaping pupil, perforating fibromembrane in the pupillary area. The IOL was secondarily implanted into the posterior chamber, and the patients were followed up in 3 - 32 months. RESULTS: The surgery was successful in all patients. The postoperative visual acuities in 71 eyes were >or= 0.5 (82.6%), including >or= 0.9 (39.5%) in 34 eyes and <or= 0.2 in 15 eyes (17.4%). After IOL implantation, the IOL correctly centered was in 68 eyes (79.1%), and deviated in 18 eyes (20.9%). Anterior chamber hemorrhage occurred in 5 eyes, 4 of them were recovered by conservative treatment and the blood membrane in another eye was sucked out through its primary incision. All patients had slight postoperative inflammation and without severe long term complications. CONCLUSION: With the support of enough fibromembrane in pupillary area, anterior segment reconstruction and secondary posterior chamber IOL implantation can be performed, thus IOL suture fixation is not necessary, and its associated complications can be avoided.

Adolescent↗

PubMed2000

[Studies on intercellular communication of rabbit lens epithelial cells in vitro].

OBJECTIVE: To investigate the intercellular communication in rabbit lens epithelial cells and effect of dexamethasone and heparin on it. METHODS: Rabbit lens epithelial cells were cultured and exposed to different concentrations of dexamethasone (10, 100, 300 mg/L), heparin (1 x 10(5), 2 x 10(5), 4 x 10(5) U/L) for 48 hours at 37 degrees C. The fluorescence redistribution after photobleaching (FRAP) was used for the analysis. The mean fluorescence recovery rate (MFRR, %/min) of the cells labelled with 6-carboxy fluorescein diacetate (CFDA) after photobleaching was measured with laser scanning cytometry ACAS Ultima. RESULTS: MFRR (%/min) of the cells after exposure to dexamethasone was 0.375 +/- 0.236 in the control group, 0.491 +/- 0.239 in the group of dexamethasone 10 mg/L, 0.996 +/- 0.447 in the group of dexamethasone 100 mg/L, 0.984 +/- 0.379 in the group of dexamethasone 300 mg/L, respectively (F = 26.07, P < 0.05). The MFRR after exposure of heparin was 0.375 +/- 0.236 in the control group, 0.694 +/- 0.491 in the group of heparin 1 x 10(5) U/L, 1.097 +/- 0.504 in the group of heparin 2 x 10(5) U/L, 1.082 +/- 0.501 in the group of heparin 4 x 10(5) U/L, respectively (F = 19.01, P < 0.05). CONCLUSION: It is discovered that there is intercellular communication in rabbit lens epithelial cells with FRAP analysis. Dexamethasone and heparin can enhance the intercellular communication of rabbit lens epithelial cells in dose dependent manner.

Animals↗

PubMed2000

[Inhibition of hTR activity for suppression of lung cancer cell proliferation using antisense phosphorothioate oligonucleotides].

OBJECTIVE: Telomerase activity was measured in 8 lung tumor cell lines and transfected antisense phosphorothiate oligodeoxynucleotides (anti-PS-ODN) of hTR as therapeutic agents into target cell LTEP-a-2 to investigate the inhibitory effect on telomerase activity and tumor cell growth. METHODS: 1. Telomerase activity assay in 8 human lung tumor cell lines using telomerase PCR ELISA. 2. Synthesized anti-PS-ODNs of hTR and random PS-ODN transfected with Clonfectin into LTEP-a-2 cell lines for 72 hr. 3. Measure telomerase activity by telomerase PCR ELISA, SDH activity by MTT assay and cell growth. RESULTS: Eight cell lines showed positive expression of telomerase activity. Various anti-PS-ODNs could inhibit telomerase activity, SDH activity and cell growth. The inhibition became more marked with the increase of anti-PS-ODNs concentrations. Concentrations of 5 - 40 micromol/L anti-PS-ODNs of hTR specifically reduced the telomerase activity by 25.7% - 84.0%. PS-ODNs of anti-hTR were also able to reduce SDH activity by 19.4% - 74.7% at 5 - 40 micromol/L. The dose of 5 - 40 micromol/L PS-ODNs of anti-hTR had the ability to inhibit cell growth by 14.8% - 72.5%. The results indicate that random sequence of PS-ODN(9) failed to inhibit telomerase, SDH activity and cell growth. A statistically significant difference exists between random PS-ODN and three anti-PS-ODNs (P < 0.01). CONCLUSIONS: Human lung tumor cell lines express high telomerase activity. PS-ODNs of anti-hTR had the ability to inhibit telomerase and reduce LTEP-a-2 cell growth and metabolism.

Adenocarcinoma↗

PubMed2000

[Distribution of minimal residual leukemia in Brown Norway rats express LacZ gene].

OBJECTIVE: To investigate the distribution of minimal residual leukemia (MRL) in vivo. METHODS: The MRL model in BN rat was established by using LT12nl leukemia cell line carrying LacZ gene. The marker gene (LacZ) was detected by using reverse transcriptase polymerase chain reaction (RT-PCR) and nested PCR, X-gal staining, and cytomorphological and pathological examination. RESULTS: PCR assays showed positive result in humerus at day 4, femur at day 6, and spleen at day 9 after CTX treatment. The peak positive signal in humerus was stronger at day 9. X-gal staining showed negative in spleen at day 9. PCR showed negative results in peripheral blood and liver. CONCLUSION: PCR can be used as an effective tool to investigate the distribution pattern in experimental MRL.

Animals↗