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Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 289 records · Page 16Linked to original sources
PubMed2001

[The role of beta-catenin in the repair of the damaged airway epithelium in smoking mice].

OBJECTIVE: To evaluate the role of beta-catenin(beta-cat) in the repair of the damaged airway epithelium by comparing their expressions of beta-cat in different stages of smoking in murine model. METHODS: With HE staining, morphological changes of airway epithelium were observed microscopically in mice model at 5th week (S5 w), 10th week (S10 w) and 15th week (S15 w) of smoking. Immunohistochemistry and hybridization in situ were performed to investigate the expressions of beta-cat mRNA, beta-cat, c-Src gene and phospho-rytyrosine-protein (p-Tyr). RESULTS: Morphological changes of the airway epithelium showed predominant damage(S5 w), repair(S10 w) and excessive proliferation (S15 w) Mean beta-cat OD values at S5 w, S10 w and S15 w were 0.097 +/- 0.007, 0.160 +/- 0.003 and 0.107 +/- 0.008, being significantly lower than the control value(0.204 +/- 0.012, all P < 0.01); The mean beta-cat mRNA OD value of S5 w, S10 w and S15 w were (0.123 +/- 0.011, 0.173 +/- 0.008 and 0.116 +/- 0.004) were also lower than that in control(0.223 +/- 0.008, all P < 0.01), but the OD value of S10 w was higher than those of S5 w and S15 w. OD value of S15 w was the lowest with only traced beta-cat mRNA expression in the nuclei. The expressions of c-Src and p-Tyr in normal airway epithelium(OD values: 0.048 +/- 0.015, 0.075 +/- 0.011) were significantly lower than those in S5 w(0.127 +/- 0.018, 0.112 +/- 0.012), S10 w (0.147 +/- 0.010, 0.127 +/- 0.018) and S15 w(0.147 +/- 0.010, 0.127 +/- 0.018, all P < 0.001). CONCLUSION: beta-cat may play an important role in the process of repair of airway epithelium. Downregulation of beta-cat may be caused by c-Src which phosphorylates tyrosin residues of beta-cat, leading to its degradation; Intracellular level of p-Tyr may, to some extent, reflect the functional condition of beta-cat.

Animals↗
PubMed2001

[Catalytic reduction of NO by chars loaded with Ca and Fe].

The effects of calcium and iron impregnated on coal chars as catalysts in NO-char reaction were investigated. The NO-char reaction was studied in a quartz fixed bed reactor at atmospheric pressure. Temperature programmed reaction (TPR) and isothermal reaction were used to determine the catalytic activities of calcium and iron at various atmosphere environments. The results showed that the higher the temperatures of pretreatment, the lower the catalytic activity of calcium, while the pretreatment temperatures had little effect on the catalytic activity of iron. Both calcium and iron promoted the NO-char reaction, but the catalytic activity of the latter was higher than that of the former. NO reduction by CO was strongly promoted by Fe and Ca. The addition of O2 in the char-NO-Ca or char-NO-Fe system promoted the NO reduction significantly. Oxidation/reduction mechanisms were proposed for the NO reduction by char catalyzed by Ca and Fe.

Calcium↗
PubMed2001

[Adverse effects of exposure to p-nonylphenol on reproductive system of young male rats].

OBJECTIVE: To study the adverse effects of exposure to p-nonylphenol (NP) during gestation and lactation on the reproductive system of young male rats. METHODS: Pregnant rats were administrated with p-nonylphenol, at doses of 0, 50, 100 [symbol: see text] 200 mg/kg of body weight, respectively, by gavage from the first day of gestation to the day of weaning, i.e., the 21st day after birth. The young male rats were killed at the age of 70 days and some indices related to their reproductive system (i.e., weight of the gonad, sperm counts of the epididymis, histology of the testes, et al.) were analyzed. RESULT: Weights of the testes and prostate gland decreased with the increase doses of exposed NP, their weights of the testes of 2.86, 2.98, 2.59 and 2.44 g, and those of the prostrate gland of 0.26, 0.23, 0.20 and 0.19 g, respectively. The same trend existed in daily production of sperm in the testes and sperm counts of the epididymis, with 22.46, 18.46, 17.43 and 17.26 x 10(6) sperm per gram of the testis, with sperm counts of 46.85, 39.74, 35.57 and 31.36 x 10(6) per gram of the epididymis tail. Separation of prepuce occurred on the 47.83th days and 46.31th days in the rats exposed to 200 mg/kg of NP and in the control group, respectively. CONCLUSION: NP could decrease their ability of spermatogenesis in the rats without morphological changes of spermatogenic cells of the testes and epididymis.

Animals↗
PubMed2001

[Sequence analysis of mtDNA 12S rRNA, tRNA(Leu(UUR)),tRNA(Ser(UCN))and 16S rRNA gene of 12 nonsyndromic inherited deafness pedigrees].

OBJECTIVE: To detect the relationship of mtDNA mutation with inherited deafness and the reason for pedigree's hypersensitivity to ototoxicity of aminoglycoside antibiotics(AmAn). METHODS: Pedigree investigations were conducted. The blood samples were obtained from 12 pedigrees, and DNA was extracted from the isolated leukocytes. After that, mtDNA fragments were amplified by PCR. The 1555(G), 3243(G) and 7445(G) mutations were detected by Alw 26 I, Apa I and Xba I restriction endonuclease digestion respectively, and then sequencing of 12S rRNA, tRNA(Leu(UUR)), tRNA(Ser(UCN))and 16S rRNA gene was performed. RESULTS: Restriction endonuclease digestion and sequence analysis showed that all the pedigrees carried mtDNA mutation, among them, 10 pedigrees carried 1555(G) mutation; 2 pedigrees, 7445(G) mutation; no pedigree was found to harbor the 3243(G) mutation. Sequence analysis of 16S rRNA gene showed that the mutations are 2230(G), 2230(AG), 2243(AG), 2230(AA). CONCLUSION: The pedigrees that carried 1555(G) or 7445(G) mutation showed hereditary or congenital hearing loss. The 1555(G) or 7445(G) mutation in association with 16S rRNA gene mutation led to pedigree's hypersensitivity to AmAn ototoxicity.

Base Sequence↗
PubMed2001

Effects of free radicals and amyloid beta protein on the currents of expressed rat receptors in Xenopus oocytes.

OBJECTIVE: To investigate the effects of free radicals (FRs) and amyloid beta protein 1-40 (A beta 1-40) on the functions of expressed neurotransmitter receptors (NRs) in Xenopus oocytes. METHODS: Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat brain tissues with Promega kits and microinjected into maturated Xenopus oocytes (stages V-VI) with 50 nl (50 ng) for each oocyte. The microinjected oocytes were incubated with modified Bath's solution at 19.0 degrees C +/- 1.0 degree C for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPX/XO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of A beta and SAFRs on the expressed glutamate receptor, HPX/XO and A beta 1-40 were added to incubation solution at 12 h, 24 h and 96 h before recording. RESULTS: The results showed that the oocytes expressed functional NRs originating from rat brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and gamma-aminobutyric acid (GABA). The current characteristics of expressed receptors were inward currents carried by chloride ion with their equibrilium potentials close to -22 mV. The extent of effect on the current of expressed glutamate receptor from rat brain was different among different A beta concentrations and incubation times. A beta 1-40 at a concentration of 20 nmol/L had little effect on the currents of expressed rat brain glutamate receptors up to 24 h of incubation period; but the currents of glutamate receptor were significantly decreased (25% off, P < 0.01) in the treatment of 60 nmol/L A beta 1-40 over 24 h. Moreover, when 20 nmol/L A beta 1-40 was co-incubated over 12 h with SAFRs produced by the reaction system of HPX/XO, it was found that the currents of expressed rat brain glutamate receptors had been changed markedly. When the oocytes were co-treated with 60 nmol/L A beta 1-40 and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P < 0.05), and the decreased percentage reached 52% over 24 h co-treatment with 60 nmol/L A beta 1-40 and SAFRs. In addition, vitamin E had a partial effect against this inhibitory effect. CONCLUSION: The results suggest that A beta has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects can be antagonized by vitamin E. These imply that A beta may play a role via inhibiting receptor function in the pathophysiology of Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed2001

Clinical and familial study of arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVE: To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. RESULTS: All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). CONCLUSION: Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle.

Adolescent↗
PubMed2001

[Application of inter-fluorescence in situ hybridization of chromosome 13/21 alpha satellite probe in amniotic cells for prenatal diagnosis trisomy 21 syndrome].

OBJECTIVE: To investigate the prenatal diagnosis of trisomy 21 syndrome using chromosome 13/21 alpha satellite probe fluorescence in situ hybridization (FISH) on uncultured interphase cells from amniotic fluid. METHODS: The interphase amniocytes of 10 fetuses who were detected normal and 3 fetus who were detected trisomy by prenatal cytogenetic diagnosis were selected. We did FISH which used chromosome 13/21 alpha satellite probe directly on the uncultured amniocytes of these 13 samples. RESULTS: The total rate of the hybridization was 36.7% and 38.6% in control group and observation group respectively, showed no significantly difference. There were four signals in the nucleus, two groups were 36.5% and 3.9% respectively, there were five signals in the nucleus, two groups were 4.0% and 36.1% respectively. The control group and observation group showed significantly difference by the statistical chi 2 values (P < 0.01). Trisomy 21 syndrome was diagnosed when nucleus of five signals accounted for more than 36.1%. CONCLUSION: FISH with Chromosome 13/21 alpha satellite probe is a valuable method for rapid prenatal diagnosis of trisomy 21 syndrome.

Amniotic Fluid↗
PubMed2001

[Biomechanical properties of human umbilical vessels at different gestational ages and their clinical significance].

To provide theoretical data on biomechanical properties for the clinical application of human umbilical artery and umbilical vein. The calculation of the compliance of fetal umbilical artery and umbilical vein was made on the basis of measuring the pressure-volume relationship of the umbilical artery and umbilical vein collected from 50 normal fetuses and newborns of abortion and normal labor whose gestational ages ranged from 24 weeks to 42 weeks. It was found that the P-V relationship of umbilical artery and umbilical vein corresponded to parabolic curve and the compliance increased gradually with the growth of the gestational age, but when the gestational age was beyond 39 weeks the compliance began to decrease gradually. The compliance of umbilical vein is twice or triple as large as that of umbilical artery. Human umbilical artery and umbilical vein are good substitute materials for arterial grafts. In transplantation, two factors should be considered, first, the correspondence between the compliance of umbilical vessels and that of host artery; second, the relationship between the compliance and gestational age. We suggest that it be better to use selectively the umbilical artery and umbilical vein with a gestational age from 37 weeks to 40 weeks as the transplanting material.

Biomechanical Phenomena↗
PubMed2001

[The effect of Paeonol on erythrocyte deformability determined by micropipette aspiration technique].

OBJECTIVE: The effect of Paeonol (PAE) on erythorcyet(RBC) deformability was studied in order to provide experimental data for the application in clinic and the evaluation in pharmacological action. METHODS: Micropipette Aspiration Technique was used to determine the RBC deformation length. The method of calculation was also simplified and a new apparent deformation Index(ADI) was defined. RESULTS: PAE could increase the ADImin and ADImax and decrease Tmax significantly. CONCLUSION: PAE has the effect of deformational ability on RBC. Micropipette aspiration technique is a feasible method for determining the effect of traditional Chinese medicine on erythrocyte deformability.

Acetophenones↗
PubMed2001

[Soil and water loss from cultivated slope land derived from granite under different cropping systems in Three-Gorges reservoir areas].

The water and soil loss caused by cultivation on slope land derived from granite under different cropping systems in the Three-Gorges reservoir area was analyzed based on the data from localized observation. The results showed that in this area, proximately 60% of total annual rainfall, distributed in May to August, and 60% of soil erosion occurred in these four months, with 50% in June and July. The coverage rates under different cropping systems differed significantly, e.g., triple-cropping systems and inter-croping system with perennial plants (grass and day lily) had a bigger covering than double-cropping systems. The soil loss under cropping system with peanut was much lower than that with sweet potato, because the covering rate of the former was higher than that of the latter in summer raining season. The sequence of soil and nutrient loss for different cropping systems was rape (wheat) sweet potato > rape(wheat)/corn/sweet potato > rape(wheat)/corn/peanut/rape(wheat)/grass/peanut/rape(wheat)/day lily/peanut. It was concluded that soil loss from cultivated slope land could be controlled below a permissible value, if rational cropping and management systems were adopted.

Agriculture↗
PubMed2001

Early monitoring of P(ti)O(2), P(ti)CO(2), pH and brain temperature in patients with brain injuries and the clinical significance.

OBJECTIVE: To explore the regulation of early brain tissue metabolic changing after brain injuries and the clinical significance. METHODS: There were 17 patients with brain injuries. Early dire ct monitoring of P(ti)O(2), P(ti)CO(2), pH and brain temperature, dynamic observation of the relation between various parameters and clinics after brain injuries were performed. RESULTS: Early changes of P(ti)O(2), P(ti)CO(2) and pH were closely correlated with outcome. The death rate obviously increased when P(ti)O(2) was continuously lower than 9 mmHg within 24 hours after injuries. Secondary brain injury prolonged and aggravated brain tissue metabolic disturbance. When intracerebral pressure was over 30 mmHg P(ti)O(2) began to decrease. The brain temperature in brain death patients was evidently lower than axillary temperature. CONCLUSIONS: The direct monitoring of P(ti)O(2), P(ti)CO(2), pH and brain temperature is safe and accurate and can find early anoxia da mage to brain tissue and provide reliable basis for clinical therapy. It ha s an instructive significance in selecting and studying a new treatment method in brain injuries. And it can be taken as a criterion in clinical judging brain deaths.

Adult↗
PubMed2001

The effect of antihypertensive treatment on cardiovascular events--a meta-analysis of four clinical trials in China.

OBJECTIVE: The pooled results of four large-scale clinical trials of antihypertensive treatments carried out in China were assessed, with an overall study population of 10,457 patients. METHODS: The fixed effect model was used for data analysis. RESULTS: A pooled analysis at the individual level showed that the average time of treatment was 3.4 years, after which an average reduction in blood pressure of 9/4 mmHg was found. The meta-analysis showed that stroke was reduced by 36% (95% CI 25%-46%, P < 0.001), cardiovascular death and total deaths were reduced by 22% and 20% respectively (P < 0.05) and total cardiovascular events were significantly reduced by 33% (P < 0.001). However, the reduction in coronary heart disease (CHD) was much smaller and was not statistically significant (P > 0.05), whereas the significant reduction in stroke was epidemiologically expected. CONCLUSION: The benefit of antihypertensive treatment obtained was mostly due to a reduction in the incidence of stroke.

Antihypertensive Agents↗
PubMed2001

[Retrospective clinical analysis of the emergent comprehensive repair of electrical injury].

OBJECTIVE: To summarize the experience with clinical emergent comprehensive repair of electrical injury. METHODS: One hundred fifty five cases of electrical injury during past 14 years were analyzed in terms of the emergent repair methods on the basis of medical records and photographs. RESULTS: In this group of patients the average interval between injury and hospitalization was 14.9 +/- 21.5 hours, And 108 cases (70%) were admitted to hospital within 2 hours post injury. The average time between admission and first operation was 3.74 +/- 9.89 hours, and 70% of them was within 1 hour after admission. Four hundred and fifty nine wounds were debrided and 296 strips of tendons, 19 strips of blood vessels, 196 pieces of bone or joints and 16 strips of nerves, which were exposed, devitalized or necrotic, were saved. The grafting repair of tendons, bones, nerves and blood vessels was done in 24 case times. Three hundred and ninty eight tissue flaps were employed in 459 wounds. CLS (NS + Lidocaine + amphicol) solution was employed to irrigate underneath the flaps for 24 similar 96 hours or longer. Composite dan -- shen root (scatellaira indica) solution was given to all the patients by injection. As a result, the excellent rate of function and contour was 84.8%. The unsatisfactory and amputation rate was 9.6%. The rate of extremity and/or finer amputation was 1.8%. The rate of total limb loss including those lost instantly after injury was 9%. CONCLUSION: Emergent comprehensive management of electrical injury was a feasible and effective method for decreasing extremity loss.

Adolescent↗
PubMed2001

[An Experimental Study on the diagnosis of high voltage electrical injury by means of biological oxygen consumption measurement].

OBJECTIVE: To investigate the degrees of the degeneration or the necrosis of muscle tissue injured by high voltage electricity as determined by biological oxygen consumption measurement. METHODS: An animal model with high voltage electricity designed in our laboratory was employed in the study. Muscle tissue sized 12 mm x 10 mm x 1 mm at electric burn produced 5 spots of the rabbit injured legs was harvested for the measurement of tissue oxygen consumption for 100s at 2, 8, 14, 24, 48 postburn hours and 5 postburn day. At the same time histological examination was made. RESULTS: One hundred and eighty two pieces of tissue samples were examined. Among them 20 samples with oxygen consumption below 8.7 kpa/100s (43.5%) showed necrosis under LM, while 157 samples with oxygen consumption of 16.9 to 8.78 kpa/100s (84% similar 44%) showed histological necrosis and different degrees of mixed degeneration and normal tissue, and 5 samples with oxygen consumption above 17 kpa/100s (85%) showed normal histological structure. CONCLUSION: The lower the tissue oxygen consumption was, the more severe the tissue degeneration and necrosis were. Oxygen consumption measurement could be valuable in the determination of the degree of tissue injury inflicted by electricity in terms of its convenience, rapidity and accuracy.

Animals↗
PubMed2001

[Apoptosis of bone marrow cells aplastic anemia patients treated with cyclosporin A].

OBJECTIVE: To evaluate the effects of cyclosporin A (CsA) on the apoptosis of bone marrow cells of aplastic anemia (AA) patients. METHODS: The apoptosis of and Fas antigen expression on the bone marrow mononuclear cells (MNC) in 25 AA patients and 10 normal controls were assayed by TUNEL and FACS, respectively. RESULT: The percentage of CD(34)(+) cells was decreased significantly in AA patients than in normal controls (P < 0.05), and so did the percentage of CD(34)(+)Fas(+) cells (P < 0.05). The percentage of apoptotic cells in AA patients was higher than that of controls (P < 0.01). After the patients were treated with CsA for 2 months, the percentage of apoptotic cells was decreased (P < 0.01). The percentage of CD(34)(+)Fas(+) cells was positively correlated with that of apoptotic cells in AA patients. CONCLUSION: Fas is involved in the apoptosis of CD(34)(+) cells of AA patients. CsA could reduce the percentage of apoptosis of bone marrow cells in AA patients.

Adolescent↗
PubMed2001

[The study of low dose radiation inducing hormesis effect on hematopoietic system].

OBJECTIVE: To study the hormesis effect on hematopoietic system induced by low dose radiation. METHOD: CFU-GM and BFU-E were cultured in methylcellulose semi-solid culture system, levels of GM-CSF and IL-3 were assayed by ELISA and mRNA levels of GM-CSF, G-CSF, IL-3 by in situ hybridization, narrow line hybridization and Northern blot. RESULTS: (1) The in vitro yields of CFU-GM and BFU-E from radiated mice was higher than that from the control. (2) The serum protein level of GM-CSF increased obviously than that of controls; (3) mRNA levels of GM-CSF and G-CSF were also increased. CONCLUSION: There is hormesis effect on hematopoietic system induced by low dose radiation, which may be related to the increasing of cytokines.

Animals↗