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Biomedical subjects

Q Li

Publications and source records attributed to Q Li.

At least 199 records · Page 11Linked to original sources
PubMed2001

[Fas and ICE expression in the hepatocytes of tupaia with HDV/HBV infection].

OBJECTIVE: To investigate the relationship between Fas and ICE expression and HDV infection. METHODS: HDAg, Fas, and ICE were determined in 45 liver tissue specimens of tupaia with HDV/HBV infection by immunohistochemistry. RESULTS: Fas was detected in 39 out of 45 liver tissue specimens (86.7%), and ICE in 43 (95.6%). Fas and ICE were located in the cytoplasm or/and the membrane of hepatocytes, especially in the cytoplasm. There was significant correlation between the expression of HDAg and the expression of Fas and ICE (chi(2)=29.2 and 36.2, respectively, P<0.01). CONCLUSIONS: The expression of Fas and ICE may be induced by HDAg in hepatocytes.

Animals↗
PubMed2001

[Clinical study on hepatitis D virus-positive patients died from severe hepatitis B].

OBJECTIVE: To investigate the role of hepatitis D virus (HDV) in the development of severe hepatitis B. METHODS: Seventy-six HDV-positive patients died from severe hepatitis B were compared with 244 HDV-negative patients from severe hepatitis B in clinical manifestations, signs, complications and main biochemical indexes at the same period. RESULTS: HDV-positive patients had obvious ascites, abdominal distension, digestive tract hemorrhage as compared with the HDV-negative ones (P<0.05). There were significant differences in hepatorenal syndrome, bacterial infection, manifold complications, the levels of total bilirubin and alanine aminotransferase, and the activity of prothrombin between the patients of the two groups (P<0.01). CONCLUSIONS: HDV can aggravate severe hepatitis B.

Adolescent↗
PubMed2001

Noninvasive imaging by optical coherence tomography to monitor retinal degeneration in the mouse.

PURPOSE: Optical coherence tomography (OCT) is a high-resolution imaging technique that measures the intensity of backscattered light from biological microstructures in living tissue. The objective was to evaluate OCT as a routine, noninvasive technique for quantitative measurements of retinal thickness and detachment in small animal models of retinal degenerative diseases. METHODS: An OCT scanning unit was designed and built to visualize retinal tissue from rodents at high resolution in vivo. Several normal and retinal degeneration (rd) mouse strains with different pigmentation, as well as a transgenic mouse strain that carries a wild-type beta-PDE gene in an rd/rd background, were analyzed at different ages. Retinal detachment was induced by subretinal injection of saline. Retinal function was evaluated by full-field ERG, and then each retina was cross-sectionally scanned by OCT. OCT image analysis and measurements of retinal thickness were performed. Animals were then killed and retinal histology was documented. RESULTS: OCT images of the mouse retina revealed structural landmarks allowing assignment of retinal structures. There was no difference in the OCT pattern between pigmented and nonpigmented mice. Changes in the retinal thickness measured by OCT correlated very well with the loss in function measured by ERG and histology in rd/rd and rd/rd/tg(+) transgenic mice at a variety of ages. In addition, retinal detachment caused by surgery was easily visualized and observed by OCT imaging. CONCLUSIONS: OCT imaging is applicable to the mouse retina. There is excellent agreement between the retinal thickness measured by OCT, ERG amplitude, and retinal histology, thus validating OCT imaging as a sensitive and noninvasive tool for monitoring the structural progression of retinal diseases in rodent models. OCT also appears useful for visualizing retinal detachments in the mouse.

Animals↗
PubMed2001

[The measurement of intra-cellular AOX in recombinant Pichia pastoris].

The activities of intracellular alcohol oxidase(AOX) in recombinant P. pastoris expressing Pro-UK were determined by a self-designed dissolved oxygen measuring equipment. The enzyme vitality and specific enzyme vitality were defined nd the condition for detecting the enzyme vitality was also established. The experimental results showed that with a certain quantity of biomass in a phosphate buffer containing methanol, the consuming rate of dissolved-oxygen reflected the enzyme vitality of intracellular AOX. It was also found that the pH of the buffer could be very freely between 4.7 and 7.4 and the suitable optical dersity of cell concentration at 600 nm was between 0.5 and 2.0. Furthermore, the values of qo2max and Km of AOX versus oxygen consumption, which were 0.409 s-1 and 0.16 respectively, were calculated. It is a simple and sensitive and feasible method for quick measuring of AOX.

Alcohol Oxidoreductases↗
PubMed2001

[The chemical decomposition of glutamine and its effect on hybridoma cell culture].

The chemical decomposition of glutamine is a first-order reaction. Its reaction constants under storage and culture conditions were determined as 0.0009 h-1 and 0.0032 h-1 respectively. Batch culture of hybridoma cell C50 with different initial contents of glutamine helped to understand its real metabolic characteristic. The results show that when the initial concentration of glutamine is lower than 5 mmol/L, more than 80% is used by cells. And the lower the initial content, the more being used. As the initial glutamine concentration increases, the ratio of its utilization decreases. When it reaches 10 nmol/L, the ratio decreases dramatically.

Ammonia↗
PubMed2001

Subcellular expression of UGT1A6 and CYP1A1 responsible for propofol metabolism in human brain.

AIM: To observe the subcellular expression of UDP-glucuronosyltransferase 1A6 (UGT1A6) and cytochrome P-450 1A1 (CYP1A1) mRNA in the human brain and investigate the effect of brain on extrahepatic metabolism of propofol. METHODS: Fifteen patients scheduled for craniotomy under propofol anesthesia were selected. Brain tis sue was taken and blood samples from the radial artery and the internal jugular vein were drawn simultaneously. PCR technique was used to detect UGT1A6 and CYP1A1 mRNA in the microsomes and mitochondria. Enzymatic activities were assayed. Blood propofol and propofol-glucuronide concentrations were measured with HPLC and GC, respectively. RESULTS: UGT1A6 mRNA was located mainly in the microsomes, and CYP1A1 mRNA was mainly in the mitochondria. The higher blood concentration of propofol and lower blood concentration of propofol-glucuronide were observed from the radial artery than from the internal jugular vein, respectively. The Km of UGT1A6 and CYP1A1 was (0.74 +/- 0.21) mmol and (548 +/- 50) mmol, respectively. The Vmax was (536 +/- 98) nmol . h-1 . mg-1 and (37 +/- 5) nmol . h-1 . mg-1, respectively. CONCLUSION: The human brain is an important organ for extrahepatic metabolism of propofol. The metabolism occurs within microsomes and mitochondria in brain.

Adult↗
PubMed2001

[Expression of ADAM12 (Meltrin-alpha) gene in giant cell tumor of bone].

OBJECTIVE: To detect expression and location of ADAM12 (meltrin-alpha) gene in giant cell tumor of bone and to study its effect on the formation of multinucleated giant cells in the tumor. METHODS: ADAM12 mRNA was detected by RT-PCR and RNA in situ hybridization in 18 cases of giant cell tumors, 6 cases of cultured tumor cells, 2 specimens of embryonic muscle tissue and 5 specimens of adult muscle tissue. RESULTS: RT-PCR showed that 12/18 (67%) cases of giant cell tumor of bone expressed ADAM12 mRNA. RNA in situ hybridization demonstrated positive ADAM12 mRNA in 12 cases of the detected tumors. The ADAM 12 mRNA positive signal was localized in the cytoplasm of almost all multinucleated giant cells and mononuclear stromal cells. However, the expression of ADAM12 mRNA decreased gradually, and eventually lost with increased passages of tumor cells and the disappearance of multinucleated giant cells in the culture. CONCLUSION: Multinucleated giant cells probably originated from the fusion of mononuclear stromal cells and ADAM12 may participate in the fusion process.

ADAM Proteins↗
PubMed2001

[The relationship between bronchial hyperresponsiveness and chronic obstructive pulmonary disease].

OBJECTIVE: To explore the relationship between bronchial hyperresponsiveness and chronic obstructive pulmonary disease (COPD). METHODS: 154 smokers with COPD (FEV1/FVC < 70%) served as a study group and 154 smokers without COPD as a control group and 23 never-smokers as a healthy control group from 23 villages in Fangshan Distract, Beijing in June, 1996. The patients with self-reported and doctor-diagnosed asthma were excluded from participants. Those subjects were divided into a positive group and a negative group based on methacholine bronchial responsiveness. All subjects were worked up in May, 2000. RESULTS: (1) Baseline case-control study: The positive rate of bronchial hyperresponsiveness was 78% in the study group, PC20 = (1.4 +/- 1.6) g/L; however 28% of the matched group were positive, PC20 = (2.7 +/- 2.3) g/L, (P < 0.001); (2) Prospective study: Of 154 pairs case-controls 241 subjects were followed up in May 2000. The rate of following up was 78.2%. The incidence of COPD was 23.7% in 38 subjects without COPD with positive hyperresponsiveness, however incidence of COPD was 9.5% in 84 subjects without COPD with negative hyperresponsiveness (P = 0.036), the relative risk (RR) = 2.5. The rate of FEV1/FVC > or = 70% was 12.9% in 93 patients with COPD and positive hyperresponsiveness, however it was 30.8% in 26 patients with COPD and negative hyperresponsiveness (P = 0.031). CONCLUSION: In smoking population, the bronchial hyperresponsiveness lead to more chronic obstructive pulmonary disease and it may be one of the susceptible risk factors for COPD.

Bronchial Hyperreactivity↗
PubMed2001

[A comparative clinical study of carboplatin solution and carboplatin powder].

OBJECTIVE: To observe the efficacy and side effects of carboplatin solution in comparison with carboplatin powder. METHODS: A multicenter, open randomized controlled trial was carried out. A total of 121 patients with small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) and breast cancer (BC) were randomized into carboplatin injection group (study group) and carboplatin powder group (control group), treated with CE, CIE and CAF protocol, respectively. The same drugs and dosage were used in the two groups. RESULTS: The response rate of the study group and the control group was 94% and 67% in SCLC (P > 0.05), 12% and 22% in NSCLC (P > 0.05) and 71.4% and 67% in BC (P > 0.05), respectively. The major side effects were myelosuppression and gastrointestinal reactions, the frequency and intensity of which were statistically not different in the 2 groups of patients. CONCLUSION: Carboplatin solution is as effective as carboplatin powder for the treatment of cancer.

Antineoplastic Agents↗
PubMed2001

[Apoptosis-related genes cloned by improved subtractive hybridization].

OBJECTIVE: To clone apoptosis-related genes induced by all-trans retinoic acid (ATRA) from human breast cancer cell line MCF-7, and to analyze the association between the cloned genes and apoptosis. METHODS: An apoptotic cell model of MCF-7 cells was constructed with ATRA induction. The apoptosis-related genes were cloned by improved PCR-based subtractive hybridization. RESULTS: Twelve differentially expressed clones were screened out. After exclusion of false positive clones by reverse dot blotting, 5 clones containing fragments of 0.5-1.5 kb were sequenced. The results of sequencing were compared with BLAST. A novel gene, named apmcf-1, coding for 47 amino acids was identified. This gene was accepted by GenBank, (Accession number: AF141882). The result of reverse dot blotting showed that it was related to apoptosis. The other 4 genes were already known. Three of them were related to apoptosis as previously reported. Two of them, hsp-90 and rb-L3, had little information about their relationship with apoptosis. CONCLUSION: ATRA-induced tumor cell apoptosis is a complex process with multiple genes involved.

Apoptosis↗
PubMed2001

The association between PPP1R3 gene polymorphisms and type 2 diabetes mellitus.

OBJECTIVE: To detect the relationship between the polymorphism of the glycogen-targeting regulatory subunit of the skeletal muscle glycogen-associated protein phosphatase 1 (PPP1R3) gene and type 2 diabetes by case-control study. METHODS: We genotyped the PPP1R3 gene Asp905Tyr polymorphism and a common 3'-untranslated region AT (AU)-rich element (ARE) polymorphism in 101 type 2 diabetic patients and 101 controls by oligonucleotide ligation assay (OLA) and polyacrylamide gel elecrophoresis, respectively. RESULTS: Subjects with Tyr/Tyr genotypes whose body mass index (BMI) < 25 were used as the reference group. Those whose BMI > or = 25 with Asp905 had a 3.66-fold increase (95% CI: 1.48-9.06, P = 0.005) in type 2 diabetes risk. No association was found between 3'UTR ARE polymorphism and type 2 diabetes mellitus (OR = 1.15; 95% CI: 0.62-2.14, P = 0.65). CONCLUSION: A joint effect between the Asp905 and BMI increases the risk of type 2 diabetes, and Asp905Tyr and ARE polymorphism of PPP1R3 gene are not the major diabetogenic gene variants in Chinese population.

AT Rich Sequence↗
PubMed2001

[Effect of different time intervals on the fracture strength of die stone materials].

OBJECTIVE: To evaluate the fracture resistance of three types die stone materials at different time intervals. METHODS: Maxillary master casts were made of ploymerized methyl methacrylate resins. Three types die stone materials were used. A total of 144 casts were prepared, separated and tested on the self-made testing machine at 0.5, 1.6 and 16 hours to measure the resistance to fracture. RESULTS: The data were analyzed with ANOVA at alpha = 0.05 and n = 12. Results showed that the cast fracture strength was affected by cast material and setting time obviously. CONCLUSION: It is recommended that the cast setting time should be 6-16 hours.

Biomechanical Phenomena↗
PubMed2001

Hemodynamic effects of agmatine in Dahl salt-sensitive hypertensive and Dahl salt-resistant rats.

The hemodynamic effects of agmatine were investigated in anaesthetized Dahl salt-sensitive (DS) hypertensive and Dahl salt-resistant (DR) rats. The results are as follows. (1) Agmatine (1, 10, 20 mg/kg i.v.) decreased heart rate (HR), mean arterial pressure (MAP), left ventricular blood pressure (LVP), the first derivative of LVP (LV dp/dt), cardiac index (CI) and total peripheral resistance index (TPRI) in a dose-dependent manner in both DS and DR rats, and the decreases in MAP, LVP, +/- LV dp/dtmax and TPRI at the same dose of agmatine in DR rats were less than those in DS hypertensive rats. Specifically, agmatine at high dose (20 mg/kg) induced a delayed increment of hemodynamic parameters in DS hypertensive rats, but not in DR rats. (2) Idazoxan (2.5 mg/kg), an antagonist for I2 over I1-imidazoline receptors and alpha 2-adrenoceptor receptors (alpha 2-AR), only partially blocked the effects of agmatine (10 mg/kg). (3) Yohimbine (4 mg/kg), a selective alpha 2-AR antagonist, also partially attenuated the effects of agmatine. (4) Efaroxan (2.5 mg/kg), a selective antagonist for I1 over I2-imidazoline receptors and alpha 2-AR, could completely block the effects of agmatine. Taken together, the results indicate that agmatine can dose-dependently decrease HR, MAP, LVP, +/- LV dp/dtmax, CI and TPRI in DS hypertensive and DR normotensive rats. The hemodynamic effects of agmatine are mediated mainly by I1-IR with the participation of I2-IR and alpha 2-AR.

Agmatine↗
PubMed2001

[Projections of 5-HTergic fibers to the spinal phrenic nucleus and medullary phrenic premotor neurons in the cat].

Experiments were performed on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into the spinal phrenic nucleus. The brainstem sections were double processed for HRP histochemical staining with TMB-DAB method and 5-HT immunohistochemical staining with anti-5-HT primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-5-HT double-labeled neurons were observed mainly in the nucleus raphe pallidus. A few double-labeled neurons were also observed in nucleus raphe obscurus and nucleus raphe magnus. 5-HT immunopositive terminal fibers were observed in the vicinity of HRP single-labeled neurons (phrenic premotor neurons) located in the nucleus ambiguus and ventrolateral solitary tract nucleus. The results indicate that the 5-HTergic neurons in the nucleus raphe pallidus send axonal projections to the phrenic nucleus, and that the brainstem phrenic premotor neurons also receive 5-HTergic axonal projections.

Animals↗
PubMed2001

Afferent projection to the retrotrapezoid nucleus from respiratory related structures in the brainstem of rabbit--a retrograde CB-HRP tracing study.

Experiments were performed on 10 adult rabbits. After microinjection of cholera toxin B-subunit conjugated horseradish peroxidase (CB-HRP) into the retrotrapezoid nucleus (RTN), retrogradely labeled neurons were mainly observed in the Kölliker-Fuse nucleus (KF), the medial parabrachial nucleus (PBM) and the lateral parabrachial nucleus (PBL). A few labeled neurons were also observed in the ventrolateral solitary tract nucleus, the ambiguus and retroambiguus nuclei, and the ventromedial area of retrofacial nucleus. Labeled terminal fibers were mainly observed in the retrofacial nucleus, the ambiguus and retroambiguus nuclei, the ventrolateral area of solitary tract nucleus, and the PBL-PBM-KF. The above results show that the RTN has axonal connections with the pontine and medullary respiratory related structures.

Afferent Pathways↗
PubMed2001

Changes of blood circulation of the extremity after external fixation for tibia shaft defect: an experimental study.

OBJECTIVE: To assess and compare two approaches, end to end compression with lengthening (EECL) and segmental bone transport by lengthening (STBL), for long tubular bone defect and nonunion. METHODS: Ten goats were used to establish the bone defect model of the mid-tibia. The bone defect ends were shortened step by step with a sulcated half-ring external fixator. Changes of the blood flow of the distal extremity were measured with pulse-Doppler monitor and angiography. RESULTS: The blood flow in the distal extremity was not affected when bone defect was less than 15% of the original length. Blood circulatory disorder would appear in the distal extremity when bone defect ranged 15%-20% of the original length. The necrosis would appear in the extremity because of the blood circulatory obstacle when bone defect was more than 20% of the original length. CONCLUSIONS: EECL is an appropriate alternative of treatments if bone defect is less than 15%; while SBTL may be feasible if bone defect is over 20% of the original length. When bone defect ranges between 15% and 20%, EECL should be applied with great care on condition of keeping watch on the extremity circulation with pulse-Doppler monitor.

Angiography↗
PubMed2001

[Evaluation of p53, p21waf1, and PCNA in the diagnosis on lung cancer].

OBJECTIVE: To evaluate the diagnostic value of p53, p21waf1 and PCNA on diagnosis of lung cancer. METHODS: One hundred and fourteen lung cancer patients and 89 cases with benign pulmonary diseases were studied on the expression of p53, p21waf1 and PCNA by immunohistochemical staining. The differences of p53, p21waf1 and PCNA expression status between these two groups were compared and the diagnostic value of these three markers was evaluated. RESULTS: (1) The positive rates of p53, p21waf1 and PCNA expression in lung cancer were 47.37%, 75.44% and 80.70%, all significantly higher than that in benign pulmonary diseases (P < 0.001), with odds ratio 39.15, 5.75, 6.76 respectively. (2) The positive likelihood ratio of p53 was 21.08, higher than that of p21waf1 and PCNA. Specificity and Youden index were also higher than those of p21waf1 and PCNA, but the sensitivity of p53 was low. (3) The sensitivity and specificity of p53 and PCNA parallel test were 89.47% and 60.67% respectively. CONCLUSIONS: (1) The expression of p53, p21waf1 and PCNA in lung cancer cases were all upregulated. These three markers all seemed to have strong links with lung cancer. (2) p53 was shown a good marker for lung cancer diagnosis. (3) The diagnostic value of p53 and PCNA parallel test was rather high.

Biomarkers, Tumor↗