Biomedical subjects

Q Li

Publications and source records attributed to Q Li.

At least 451 records · Page 25Linked to original sources

PubMed1999

[Skeletal effect of xianzhen gubao on preventing prednisone-induced osteoporosis in male rats].

OBJECTIVE: To study the effect of Chinese medicine Xianzhengubao (XZGB) capsules of compound prescription on corticosteroid-induced osteoporosis in rats. METHOD: 3-month-old SD male rats were randomly divided into basal control and aging control, prednisone (4.5 mg.kg-1, ig, twice a week) and XZGB capsules were used in three different doses (0.2, 0.4, 0.8 g.kg-1.d-1 ig)6 times a week. All the rats were killed. On the 90th day afteradministration. The proximal tibiae were processed in undecalcified sections at a thickness of 4-10 microns for histomorphometric analysis. RESULT: Compared with the aging controls corticosteroid reduced markedly the trabecular bone mass due to increase of bone resorption and decrease of bone formation (%Tb. Ar 52.9%). Treatment with XZGB capsules in high doses increased significantly the trabecular area as compared with the hormone control(% Tb. Ar + 91.2%). The protective mechanism of XZGB capsules mainly consists in suppressing bone resorption and mildly increasing bone formation in rats. CONCLUSION: Xianzhen gubao capsules have an effect on preventing bone loss in rats induced by corticosteroid, and higher doses produce greater effect.

Animals↗

PubMed1999

[The effects of fluoride on the bonding strength of brackets].

OBJECTIVE: To evaluate the effect of using fluoride during and after etching on the bonding strength of brackets. METHODS: 45 extracted human premolar were divided into three groups: Group 1, control, not applying fluoride. Group 2, applying fluoride during etching. Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively and stored in water for 24 hours. Then brackets bonding strength were measured. RESULTS: The results showed that there was not significant difference among the three groups. CONCLUSION: Fluoride can be used to prevent enamel white spot.

Acid Etching, Dental↗

PubMed1999

[Scanning electron microscopy study on different orthodontic methods of using fluoride in enamel white spot prevention].

OBJECTIVE: To determine which method of topical fluoride application could make the enamel uptake more fluoride. METHODS: 12 extracted human premolars were divided into three groups of 4 teeth each: Group 1, control and not applying fluoride; Group 2, applying fluoride during etching; Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively. The specimens were then examined with scanning electron microscopy. RESULTS: The results showed that there were more reaction products on the enamel surface of Group 3. CONCLUSION: There was more fluoride uptake into the enamel treated with fluoride after etching.

Acid Etching, Dental↗

PubMed1999

[A retrospective study of morphologic basis for the extraction decision in Class II, division 1 malocclusion].

OBJECTIVE: To compare the dentofacial characteristics of persons with Class II, Division 1 malocclusion treated with either an extraction or a nonextraction approach. Such comparison might help identify which parameters influence the extraction decision. METHODS: Lateral cephalograms were available on 81 cases of Class II, Division 1 malocclusion, 42 were treated with 4 premolar extractions and 39 were treated with non-extraction. The cephalometric analysis of West China University of Medical Sciences and Model Analysis were used, RESULTS: Patients in the extraction group had larger FMA, FMIA and lower anterior facial height. In the group of extraction, the upper anterior teeth tipped more anteriorly, and the tooth size-arch length discrepancy and the depth of Spee curve were greater significantly. But the saggital discrepancy and soft tissue's profiles had no significant difference between two groups. CONCLUSION: The stability of the triangle of Tweed, the tooth size-arch discrepancy and the depth of Spee curve were the keys to decide weather extraction or not.

Adolescent↗

PubMed1999

[Effect of lipopolysaccharide on recombinant human osteogenic protein-1-induced responses in human dental pulp cells].

OBJECTIVE: To investigate the effects of lipopolysaccharide (LPS) on recombinant human osteogenic protein-1 (rhOP-1) induced proliferation and differentiation. METHODS: Measured MTT, alkaline phosphatase (ALPase) activity and osteocalcin content of human dental pulp cells. RESULTS: Low-dose LPS (1 microgram/ml) caused co-operative effect with low concentration of rhOP-1 to enhance human dental pulp cell proliferation and ALPase activity, but not to osteocalcin, whereas, high-dose LPS (100 micrograms/ml) significantly inhibited the proliferation, ALPase activity and osteocalcin with or without rhOP-1. CONCLUSION: The role of LPS in caries-induced reparative dentin might be a significant determinant.

Alkaline Phosphatase↗

PubMed1999

[Observation on the immune function of circulating red cells of patients with periodontal diseases].

OBJECTIVE: To find out the relation between the causes of periodontal diseases and the immune function of red blood cells (RBC). METHODS: The functional state of SOD activity, red blood cell C3b receptor rosstte (C3bR), red cell immune complex rosstte (RBCICR), RBC immune adherence enhance factor (RFER) and RBC immune adherence inhibitor factor (RFIR) of red cells from the systemic circulation of patients with periodontal diseases were determined and compared with the normal control group. RESULTS: The SOD activity C3bR and RFER of red cells were lower, while RFIR and RBCICR were higher for patients with periodontal diseases comparing to the normal control. CONCLUSION: It indicates that the compromised function of red cells may contribute to the initiation and development of periodontal diseases.

Adult↗

PubMed1999

[Analysis of measured results of transient-evoked otoacoustic emissions].

OBJECTIVE: In order to provide grounds for clinical diagnosis, the normal sensitive parameters of the transient evoked otoacoustic emissions (TEOAE) in normal ears were studied. METHOD: 60 ears with normal hearing subjects using ILO-88 otodynamic analyzer system were measured, the click stimuli level is 80 dB SPL and the stimuli pattern used non-linear model. RESULT: Analysis of the normal values of the stability, A-B difference, response amplitude, wave reproducibility, band reproducibility and band SNR, dominant frequencies were obtained. CONCLUSION: The findings from comprehensive analysis of spectrum, response amplitude and reproducibility can be used as main sensitive parameters to evaluated whether or not of normal-hearing.

Acoustic Stimulation↗

PubMed1999

[Diagnostic significance of transiently evoked otoacoustic emissions in meniere's disease].

OBJECTIVE: To judge the diagnostic significance of TEOAE by glycerol test in Meniere's disease. METHOD: TEOAE were recorded from all testing ears with or without Meniere's disease. RESULT: The wave reproducibility, amplitude of response, band reproducibility, band SNR in ears of affected ears with meniere's disease after administration of glycerol were increased, about which the parameters of affected ears in positive glycerol test were obviously higher than that in negative glycerol test. All parameters in normal ears with Meniere's disease increased too, and there have the changes of main frequency. CONCLUSION: TEOAE records of glycol test may be more sensitive and more simple than pure tone audiometry in diagnosing meniere's disease, and should be used more extensively.

Audiometry, Pure-Tone↗

PubMed1999

Effects of 16O+6 ion irradiation on human sperm spontaneous chemiluminescence, motility, acrosome reaction and viability in vitro.

Effects of 16O+6 ion irradiation with different doses on human sperm spontaneous chemiluminescence (SCL), motility, acrosome reaction (AR) and viability were examined. Spermatozoa were irradiated with 0, 0.25, 0.5, 1, 2, 4, 8, 16, 32, or 64 Gy 16O+6 ion beam at the energy of 3.17 MeV/u. After irradiation, samples were analyzed by SCL measurement at 1, 2 and 3 h of incubation; motility was determined by the transmembrane migration method within 2 h of incubation; the percentage of AR and viability was evaluated by the triple-stain technique at 3.5 h of incubation. The results showed: sperm SCL was significantly increased with irradiation doses and the lowest effective dose was 0.5 Gy; compared with controls, the transmembrane migration ratio of spermatozoa progressively elevated with irradiation doses at 0.5, 1, and 2 Gy; the percentage of sperm AR markedly increased in 0.5-4 Gy irradiation and the optimal dose was 2 Gy, and then significant decreased with further increase of irradiation doses; the viability had no significant change within 0.25-8 Gy, but was progressively decreased at 16, 32 and 64 Gy. These data suggested that heavy ion at low doses increased motility and AR, whereas had deleterious effects at higher doses, which are associated with free radical reactions induced by heavy ion irradiation.

Acrosome Reaction↗

PubMed1999

Effects of ginsenosides on myocardial reperfusion arrhythmia and lipid superoxidation in high cholesterol diet rats.

To explore the effects of GSL on myocardial reperfusion arrhythmia and lipid superoxidation in high cholesterol diet rats. Hyperlipidemia model was set up with administered high cholesterol emulsion 15 ml/kg to rats orally for 14 days. In GSL group, rats were given GSL i.p. 75 mg/kg simultaneously when administered high cholesterol emulsion. The experiment of myocardial ischemia reperfusion was performed on all rats. The results showed: (1) After administration of high cholesterol emulsion to rats orally for 14 days, hyperlipidemia model was set up successfully, simultaneously treatment with GSL. It lowered serum lipid; (2) In hyperlipidemia state, serum MDA increased (p < 0.01, SOD and NO decreased markedly (p < 0.01 and p < 0.05 respectively) after 2 h of myocardial reperfusion; the rate of reperfusion arrhythmia (RPAr) increased within 10 min of reperfusion, four out of nine rats died of ventricular fibrillation (VF); and (3) GSL decreased MDA, increased SOD and NO after 2 h of myocardial reperfusion. All changes were significant (p < 0.01); the rate of RPAr decreased, no VF occurred and all rats survived. Hyperlipidemia aggravated myocardial ischemia reperfusion injury and increased the incidence of RPAr. The results suggested that GSL reduced myocardial ischemia reperfusion injury and RPAr in high cholesterol diet state through antiperoxidating and inducing the production of NO.

Animals↗

PubMed1999

[Analysis of products of thymine irradiated by heavy ion beam with capillary gas chromatography].

In this study some chromatographic methods with capillary column, such as GC, GC-MS, GC-FTIR, were used to analyze the products of thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution. Because of the complexity and small amounts of the products after irradiation by heavy ion beams, it is very difficult to separate them, while with the methods of capillary gas chromatography this problem can be overcome. From the results of GC-MS analysis we can determine the molecular weight of the product, and from the results of GC-FTIR analysis we can get structure information of the product. By this way the products such as 5,6-dihydrothymine, 5-hydroxyl-5-methylhydantoin, 5-hydroxyl-6-hydrothymine, 5-hydro-6-hydroxylthymine, 5-hydroxymethyluracil, trans-thymine glycol, cis-thymine glycol and dimers were determined. Though these products are the same as those from thymine irradiated by gamma ray in N2O saturated aqueous solution, the mechanism of heavy ion beam interact ion with thymine aqueous solution is different from that of gamma ray. The main products from thymine irradiated by 18O8+ ion beam in N2O saturated aqueous solution are formed by hydroxyl additions between 5-6 band of thymine, while those by gamma ray are dimers of thymine.

Electrophoresis, Capillary↗

PubMed1999

[Studies on biosorption of Pb2+ by Phanerochaete chrysosporium].

The biosorption of Pb2+ from solution by Phanerochaete chrysosporium was studied. The effects on biosorption capacity of pH, Pb2+ concentration in solution, co-ion and temperature, time have been examined. The adsorption capacity was compared among the biomass harvested at various growth stages. Pretreatment of biomass by NaOH solution improved its adsorption capacity. The uptake could reach 108.4 mg/g at optimal conditions of biosorption using pretreated biomass.

Absorption↗

PubMed1999

[Detection of circulating antigen in serum and cerebrospinal fluid for diagnosis of cerebral cysticercosis].

AIM: To detect circulating antigen(CAg) in serum and cerebrospinal fluid(CSF) from patients with cerebral cysticercosis with specific antiserum by sandwich ELISA. METHODS: Antisera were prepared from rabbits immunized respectively with 3 antigens with molecule weights of 64 kDa, 53 kDa, 32 kDa-30 kDa extracted from Cysticercus cellulosae and purified by SDS-PAGE. RESULTS: When samples from patients were tested with antiserum against 53 kDa antigen, the CAg positive rate was 93.8% in serum and 91.7% in CSF of 32 patients with active cysticercosis, whereas only one positive was found in CSF in 16 patients with inactive cysticercosis. The detection rate of CAg was significantly higher with anti-53 kDa antiserum than with anti-64 kDa and anti-32 kDa-30 kDa antiserum. CONCLUSION: Sandwich-ELISA using antiserum against 53 kDa antigen to detect CAg was found to be a promising assay for diagnosis and evaluation of treatment efficacy of active cerebral cysticercosis in terms of its high sensitivity and specificity.

Animals↗

PubMed1999

[TCD functional test for vertigo induced by ischemic cerebrovascular disorders].

OBJECTIVE: To diagnose differentially the vetigo induced by some ischemic cerebrovascular disorder. METHOD: Patients with vertebrobasilar artery transient ischemic vertigo (group A), migraine (group B), hyperventilation syndrome (group C), hypertension (group D) are measured by using TCD functional examination which included blood peak velocity of systolic (Vs) and diastolic (Vd) end-period of vertibrobasilar artery of routine TCD (TCD-R), one minute hyperventilation TCD (TCD-HV) and one minute voluntary apnea TCD (TCD-B) respectively. RESULT: It showed that the Vs, Vd are decreased under the three conditions in A, B and D groups. The most apparent decrease are obversed in D group. The values of the decrease are similar between group A and B. No changes are found in C group. The abnormal Vs incidences of TCD-B measurement in group A are higher than those in group B and C, but significant lower than those in group D; and in TCD-HV test lower than group D and C, higher than group B; in TCD-R test, lower than group D, and no difference with group B and C. The abnormal incidences of Vd in group A are lower than group D and higher than group B in TCD-B test. In TCD-HV test, the group A abnormol incidences are lower than group D but higher than group B and C. In TCD-R test, the abnormal incidences are lower than group D and no difference between group B and C. CONCLUSION: The TCD measuremen is useful for differential diagnosis of vertigo induced by ischemic cerebrovascular disorders.

Brain Ischemia↗

PubMed1999

[Unfolded intraocular lens implantation through a 6 mm sutureless incision].

OBJECTIVE: To evaluate the therapeuitic effects of phacoemusification and unfolded iutraoculavr lens (IOL) implantation through a 6 mm sutureless incision. METHODS: A 6 mm sclera tunnel incision was made at 12 o'clock tangent of the posterior limbus and unfolded polymethylmethacrylate(PMMA) IOL implantation was operated in 50 cases (55 eyes); 53 eyes were finished without suture after phacoemusification and 2 eyes were done with extra capsule cataract extration(ECCE) because of the broken posterior capsular. RESULTS: Postoperatively, the visual acuity was 0.6 or more in 92.4% of the eyes and 1.0 or more in 50.9% of the eyes at one week; 0.6 or more in 98.1% of the eyes and 1.0 or more in 67.9% of the eyes at one month. The mean postoperative astigmatism was 0.63 +/- 0.36 D at one week and 0.61 +/- 0.33 D at one month. There was no statistical difference between the mean preoperative astigmatism(0.60 +/- 0.48 D) and postoperative astigmatism at one week and one month (P > 0.05). CONCLUSION: The technique of phacoemusification and PMMA IOL implantation through a 6 mm sutureless incision can reduce early postoperative astigmatism, shorten the period of visual rehabilitation.

Aged↗

PubMed1999

[Implantation of the molteno tube for refractory glaucoma following penetrating keratoplasty].

PURPOSE: To assess the surgical effectiveness of the molteno tube implantation in glaucoma secondary to penetrating keratoplasty. METHODS: 9 eyes in critical condition with glaucoma secondary to corneal graft surgery, whose intraocular pressures (IOP) have previously failed to respond to glaucoma medication, were undergone Molteno tube implantation. RESULTS: IOPs ranged from 0.8-2.8 kPa (1 kPa = 7.5 mmHg) were obtained in 7 eyes, the success rate accounted for 7/9, 2 eyes still required installation of beta-blocker, the graft rejection occurred in one eye and was remedied with medical treatment, the graft remained half-transparent in one eye. Visual acuity improved in 4 eyes, stayed the same in 4 eyes and was worse in one eye. The best corrected visual acuity over 0.05 was recorded in 4 eyes. CONCLUSION: Moltemo tube implantation is a rational and effective method for preserving a certain level of visual acuity in patients with glaucoma following penetrating keratoplasty.

Adult↗

PubMed1999

[Significance of polypeptide antigen of HCVE2/NS1 relative conservation region in detection of anti-HCV].

OBJECTIVE: In order to study the significance of HCVE2/NS1 relative conservation region antigen. METHODS: EIA was established with HCVE2/NS1 relative conservation polypeptide antigen, as well as serum HCV RNA and ALT in patients with HCV infection. RESULTS: The positive rate of 96 cases patients who were infected by HCV is 41.67%, acute 13.55% and chronic 25.04%, and we found that there were 3 cases weak positive in 40 healths; Agreement rate is 62.5% in 40 cases of the positive of anti-E2/NS1 in sera with HCVRNA, and they have relation. In ALT level in sera, acute infection of HCV is higher than chronic (P < 0.05). CONCLUSION: There are virus necleic acid in sera when anti-HCVE2/NS1 appearence positive; however, antibody of anti-E2/NS1 relative conservation region has the some neutralive actions, and this humor immunity may have the actions in clearing virus, but wether anti-body of anti-E2/NS1 relative conservation of HCV is or not neutralive antibody well be investigated further.

Adult↗

PubMed1999

[Detection of Epstein-Barr virus gene in nasopharyngeal carcinoma with neck lymphatic metastasis].

OBJECTIVE: To investigate the presence of Epstein-Barr virus(EBV) gene in neck lymphatic metastasis of nasopharyngeal carcinoma. METHODS: Fifty patients' masses in the neck were punctured and the fluids were analyzed with PCR for EBV DNA. RESULTS: Twenty seven cases showed EBV DNA positive among thirty cases of nasopharyngeal carcinoma with neck lymphatic metastasis, and the positive rate was 90%. One case was EBV DNA positive in seven cases of malignant lymphoma and the positive rate was 14.3%. One case was EBV DNA positive in eight tumor patients without NPC metastasis and the positive rate was 12.5%. Five cases with nasopharyngeal inflammation and neck lymphatic node proliferation were demonstrated to be EBV DNA negative. CONCLUSION: This technique is rapid, sensitive and specific, which is valuable clinically, especially for the diagnosis in patients with cryptic nasopharyngeal carcinoma and with neck metastasis but lack of clear original focus.

Adolescent↗