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Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 181 records · Page 10Linked to original sources
PubMed2001

[Relation between activities of hepatic and gastric alcohol dehydrogenases and formation of chronic alcoholic liver diseases].

OBJECTIVE: To investigate the role of hepatic and gastric alcohol dehydrogenases (ADH) in different pathologic stages of alcoholic liver disease (ALD). METHODS: Thirty-nine rats were divided into either model or control group at random. The ALD model was established by infusing alcohol into the stomach. The activity varieties of hepatic and gastric ADH were observed by optical microscopy after hepatic and gastric tissues had been stained by enzyme histo-cytochemistry assay and the activity alterations were also determined with a LUZEX-F analysis instrument as a semi-quantitative method. RESULTS: The activity of hepatic ADH gradually increased, but gastric ADH gradually decreased in ALD. There was a significant difference between model group and control one (P<0.05). CONCLUSIONS: The activity alterations of the hepatic and gastric ADH may play an important role in the onset and development of ALD.

Alcohol Dehydrogenase↗
PubMed2001

[Dynamic change and expression of matrix metalloproteinase-2, -9 in alcoholic liver disease in rats].

OBJECTIVE: To evaluate the dynamic change and expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in alcoholic liver disease in rats. METHODS: Alcoholic liver disease rat model was established by gavage. The expression of MMP-2 and MMP-9 was studied by immunohistochemistry, and the result was analyzed by picture quantitative analysis technique. RESULTS: The expression of MMP-2 and MMP-9 was significantly higher in rats of model group than that of control group (P<0.05). The level of MMP-2 and MMP-9 increased gradually with the progress of alcoholic liver disease. Immunoreactive MMP-2 was expressed in endothelial cells of hepatic artery and portal vein, sinusoidal endothelial cells and sinusoidal cells. Immunoreactive MMP-9 was observed in sinusoidal cells and hepatic cells around the vein. CONCLUSIONS: MMP-2 and MMP-9 increa with the progress of alcoholic liver disease. They might be involved in the development of alcoholic liver disease.

Animals↗
PubMed2001

[Intervention of Fuzhenghuayu decoction on autocrine activation of hepatic stellate cells].

OBJECTIVE: To investigate the intervention of Fuzhenghuayu decoction on autocrine activation of hepatic stellate cell. METHODS: The drug serum containing Fuzhenghuayu decoction was collected from the normal rats, and cultured with activated hepatic stellate cells (HSC) in vitro. The conditional medium from the drug serum treated HSC was collected, and added to primarily cultured quiescent HSC. The primary cell proliferation was assayed by MTT colorometric test, and the contents of type I collagen and vasular endothelial growth factor (VEGF) in the medium were assayed with ELISA. RESULTS: The coditional medium from activated HSC could stimulate the proliferation and type I collagen secretion in the quiescent HSC. The drug serum inhibited this stimulating action and VEGF secretion from activated HSC. CONCLUSIONS: Fuzhenghuayu decoction has inhibitory action on the autocrine-activating pathway of HSC. The mechanism may be associated with inhibiting the secretion of VEGF by activated HSC.

Animals↗
PubMed2001

Negative regulation of phosphate starvation-induced genes.

Phosphate (Pi) deficiency is a major nutritional problem faced by plants in many agro-ecosystems. This deficiency results in altered gene expression leading to physiological and morphological changes in plants. Altered gene expression is presumed to be due to interaction of regulatory sequences (cis-elements) present in the promoters with DNA binding factors (trans-factors). In this study, we analyzed the expression and DNA-protein interaction of promoter regions of Pi starvation-induced genes AtPT2 and TPSI1. AtPT2 encodes the high-affinity Pi transporter in Arabidopsis, whereas TPSI1 codes for a novel gene induced in the Pi-starved tomato (Lycopersicon esculentum). Expression of AtPT2 was induced rapidly under Pi deficiency and increased with decreasing concentrations of Pi. Abiotic stresses except Pi starvation had no affect on the expression of TPSI1. DNA mobility-shift assays indicated that specific sequences of AtPT2 and TPSI1 promoter interact with nuclear protein factors. Two regions of AtPT2 and TPSI1 promoters specifically bound nuclear protein factors from Pi-sufficient plants. Interestingly, the DNA binding activity disappeared during Pi starvation, leading to the hypothesis that Pi starvation-induced genes may be under negative regulation.

Arabidopsis↗
PubMed2001

Improvement of melatonin to the learning and memory impairment induced by amyloid beta-peptide 25 - 35 in elder rats.

AIM: To investigate improvement of melatonin on learning and memory impairment induced by amyloid beta-peptide 25 - 35 (Abeta25-35) in elder rats. METHODS: Step-down type passive avoidance test, shuttle-box test, and Morris water maze were used together to determine effects of Abeta25-35 and melatonin on learning and memory. Pathological changes were observed by HE, Congo red, and Ag staining. RESULTS: The elder rats were injected bilaterally Abeta25-35 20 microg into the hippocampus to induce learning and memory dysfunction. Melatonin administration (0.1, 1, and 10 mg/kg, ig x 8 d) to the Abeta25-35-treated rats prolonged the latency, shortened the total stimulating time, and decreased the number of errors in the step-down test. Shuttle-box test showed that melatonin improved amnesic rats' performance at the same doses. Melatonin (0.1, 1, and 10 mg/kg ), giving for 10 d, could enhance the spatial resolution of amnesic rats in Morris water maze test. Also in Abeta25-35-treated group, a decrease in the number of neurons in cortex and hippocampus, a massive glial reaction, and neurophilic phenomenon were detected by HE staining; the positive vascular amyloidosis by Congo red and fibrils by Ag staining were observed. Melatonin (0.1 and 1 mg/kg)could inhibit above pathological changes in Abeta25-35 group. CONCLUSION: Melatonin improved the impaired learning and memory induced by Abeta25-35 in elder rats.

Amyloid beta-Peptides↗
PubMed2001

[Diagnosis and treatment of spontaneous spinal epidural hematoma].

OBJECTIVE: To evaluate the cause of hemorrhage of spontaneous spinal epidural hematoma (SSEH), its clinical manifestations, MR images, treatment, and prognosis. METHODS: Based on literature review, we retrospectively analysed 6 patients with SSEH in terms of pathogenic mechanism, clinical features, neurological function, and the interval between the onset of SSEH and surgery and prognosis. RESULTS: SSEH was liable to occur in young people, and most of cases were acute. MR imaging showed semilunar space occupying mass in the posterior or posteriolateral part inside the spinal canal. The outcome was closely related to the interval between the onset and surgery, whereas it was not related to age, site and size of the hematoma. The better neurological state before surgery and the shorter interval between onset and operation, the better outcome in such patients. CONCLUSIONS: SSEH may be originated from venous bleeding. The process at onset and clinical manifestation depends on the blood supply of the spinal cord. The optimal diagnostic method is MR imaging. Decompression of spinal cord in time is the key procedure for improving the patients' outcome.

Adolescent↗
PubMed2001

[Gap formation features of humid evergreen broad-leaved forest in central subtropical Wawushan Mountain, Sichuan Province, China].

The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720-1750 m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics. The sampling method and canopy formation causes were also discussed. In secondary evergreen broad-leaved forest, the gap density was surprisingly only 9 per hm2 and the size of all gaps was, no more than 10 m2. Almost every gap had only one gap maker, and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap, due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm2, and 56% of the gaps had an area of no more than 40 m2. The largest gap had an area of 256 m2. The canopy gap accounted for 11.1% and expended gap occupied 19.8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105 m2, respectively. Most gaps had more than one gap maker, and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10 yr and a few were formed recently and the estimated gap formation rate was 0.01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography, climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.

Altitude↗
PubMed2001

[Antisense monocyte chemotactic protein-1 gene inhibits vein graft intimal hyperplasia in rabbits].

OBJECTIVE: To identify the effect of in vivo local expression of recombine antisense MCP-1 gene on the development of vein graft neointima formation. METHODS: Jugular vein-to-artery bypass grafting was performed on 20 New Zealand white rabbits, of which 4 grafts were transferred with LNCX vectors, 6 grafts with antisense MCP-1 (200 micrograms) by cationic liposome, and 4 grafts as controls. Fourteen days after surgery grafts were harvested. The expression of antisense MCP-1 and its effect on MCP-1 in vein grafts were detected by dot blot. Grafts were processed for morphologic evaluation and immunohistochemistry analysis. RESULTS: Antisense MCP-1 was expressed in local gene delivery group, meanwhile MCP-1 expression in vein grafts was significantly inhibited (test group, 1.227 +/- 0.362; controls, 1.981 +/- 0.394, P < 0.05). Monocytes/macrophages adherence and infiltration were prominently reduced (test group, 24.3% +/- 2.7%; controls, 36.8% +/- 2.8%, P < 0.05), and intimal hyperplasia was markedly reduced [test group, (0.65 +/- 0.08) mm2; controls, 1.27 +/- 0.15) mm2, P < 0.05]. CONCLUSION: Local expression of antisense MCP-1 in vein graft significantly reduced intimal hyperplasia with inhibition of MCP-1 expression and prevention of monocytes/macrophages infiltration.

Animals↗
PubMed2001

Effects of sex hormones on apoptosis in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

OBJECTIVE: To study the effects of dehydroepiandrosterone (DHEA) and/or estradiol (E2) on apoptosis in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: The percentage of apoptosis of PBMCs from SLE patients and healthy blood donors were examined by means of AO staining 48 h after culture with DHEA and/or E2 at physiologic or pathologic concentrations. RESULTS: The percentage apoptosis of PBMCs from SLE patients is higher than that of healthy blood donors (P < 0.01). E2, whether at physiological or at pathological concentrations, had no effects no apoptosis of PBMCs from both SLE patients and healthy donors (P > 0.05). Both DHEA and DHEA plus E2 at physiologic concentrations, had no effect on apoptosis of PBMCs from healthy donors (P > 0.05), but significantly inhibited that of SLE patients (P < 0.05); at pathologic concentrations, they promoted apoptosis of PBMCs from SLE patients as well as healthy blood donors (P < 0.05). There were no significant differences between the effects of DHEA and that of DHEA plus E2 (P > 0.05). CONCLUSION: DHEA plays an important role in the apoptosis of PBMCs from SLE patients; low serum levels of DHEA may cause accelerated apoptosis.

Adult↗
PubMed2001

Molecular epidemiology of respiratory syncytial virus.

OBJECTIVE: To determine the epidemiologic pattern of subgroups A and B and genotypes of respiratory syncytial virus (RSV) during two noncontinuous epidemics during 1990-1991 and 1997-1998 in Beijing. METHODS: Nasopharyngeal secretion (NPS) samples of RSV positive or RSV isolates tested by indirect immunofluorescence (IIF) assay were classified into subgroups A and B. Isolates of RSV were divided into at least six different lineages, designated NP1-NP6, by restriction mapping of the N gene. Np1, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates. Strains of subgroup A were further subdivided into six lineages SHL1-SHL6 on the basis of the SH gene sequence. SH lineages were closely related to each other and to NP1-NP6. Strains of SHL1, 3 and 4 were closely related and belonged to NP2, SHL2 and 6 to NP4, and SHL5 to NP5. RESULTS: Of 145 RSV NPS samples from the 1997-1998 epidemic, 83 (57.2%) were of subgroup B RSV positive, 62 (42.8%) of subgroup A RSV positive. The rate of occurrence of subgroup A to B strains was about 1:1.3. Two of 10 isolates during the epidemic were subgroup A strains, whereas 8 were subgroup B strains. The rate of occurrence of subgroup A to B strains was 1:4. Eight subgroup A strains of 10 isolates from the 1990-1991 epidermic were dominant; the proportion of subgroup A to B strains was 4:1. With 10 RSV isolates in 1997-1998, all 2 subgroup A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3. All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroup B strains all belonged to NP3. The classification of subgroups A and B deduced from NP patterns corresponded to the definition of these subgroups by monoclonal antibodies. CONCLUSIONS: These observations confirm that subgroups A and B or multiple lineages of RSV co-circulated in Beijing, but different genome types predominated each year. Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable.

Genotype↗
PubMed2001

[Determination of nitidine in different parts of Zanthoxylum nitidum].

OBJECTIVE: To determine the nitidine in different parts of Zanthoxylum nitidum (Roxb.) DC. METHODS: HPLC method was used. The column was HYPERSIL BDS C18. The mobile phase was 0.02 mol/L monobasic potassium phosphate: acetonitrile (66:34). The detective wavelength was 328 nm. RESULTS: The average recoveries and RSD for nitidine was 100.24%, 1.83% respectively. The root contained more nitidine than other parts. CONCLUSION: The method can be used for the quality control of Zanthoxylum nitidum (Roxb.) DC. The roots were the best part for medicine.

Benzophenanthridines↗
PubMed2001

Gene expression of inducible nitric oxide synthase in injured spinal cord tissue.

OBJECTIVE: To investigate gene expression of inducible nitric oxide synthase (iNOS) in injured spinal cord tissue of rats. METHODS: Thirty-six adult Sprague-Dawley rats were divided randomly into six groups: a normal group and five injury groups, six animals in ea ch group. Animals in the injury groups were killed at 2, 6, 12, 24, 48 hours after injury, respectively. A compression injury model of spinal cord was established according to Nystrom B et al, and gene expression of iNOS in spinal cord tissue was examined by means of reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Gene expression of iNOS was not detectable in normal spinal cord tissue but was seen in the injury groups. The expression was gradually up -regulated, reaching the maximum at 24 hours. The expression at 48 hours began to decrease but was still significantly higher than that at 2 hours. CONCLUSIONS: iNOS is not involved in the normal physiological activities of spinal cord. Expression of iNOS is up-regulated in spinal cord tissue in response to injury and the up-regulation exists mainly in the late stage after injury. Over-expression of iNOS may contribute to the l ate injury of spinal cord.

Animals↗
PubMed2001

[Fractionated-clamping for thoracoabdominal aortic aneurysm repair: report of 13 cases].

OBJECTIVE: Fractionated-clamping was applied to aneurysm repair in patients with thoracoabdominal aortic aneurysm(TAA), and its effects in decreasing operative mortality and severe complications such as renal failure and hemiplegia were discussed. METHODS: Using improved shunting and cross-clamping technique, we repaired 13 thoracoabdominal aortae and their branches (9 males and 4 females). TAA Crawford type: type I one case, type II two cases, type III two cases and type IV three cases. TAA dissection Debakey type: type I one case, type III four cases (including 2 of ruptured aneurysm) and aorta stenosis one case. RESULTS: Twelve procedures were performed successfully. One patient died of cardiac attack immediately before accomplishment of the operation with a operative mortality rate of 7.7% (1/13). Operative complications included acute necrotizing pancreatitis (1 case), ARDS (1), thoracic cavity bleeding (2), hemiplegia (1), and acute renal failure (1). The incidence rate of complications was significantly lower than that reported elsewhere. CONCLUSIONS: Fractionated-clamping for thoracoabdominal aortic aneurysm repair is a renovation on the basis of Crawford procedure and aorta bypass method. Clinical results demonstrated that the procedure decreases the surgical mortality and the incidence rate of dangerous complications. Fractionated clamping for aorta replacement is a reasonable procedure under general anesthesia at normal temperature.

Acute Kidney Injury↗
PubMed2001

[Protective effect of tanshinone on injured cultured PC12 cells in vitro].

OBJECTIVE: To investigate the protective effects of tanshinone on ischemia-like injury models. METHOD: Six ischemia models including hypoxia, hypoglucose, oxidant injury, calcium overload, nitric oxide neurotoxicity and glutamic acid injury were used to assay the anti-ischemic roles of tanshinone in cultured PC12 cells, by using morphological examination, MTT staining and LDH measurement. RESULT: It was found that 3. 125-200 microliters.ml-1 tanshinone possessed obvious protective effects on PC12 cells from six ischemia-like injury models. Tanshinone could increase the number of life cells and decrease LDH activity significantly, particularly in hypoxia and caffeine injured model. CONCLUSION: Tanshinone protected PC12 cells from all injury models effectively in vitro. Its action may mainly focus on inhibiting development of the primary period of ischemia injury and calcium overloading injury.

Abietanes↗
PubMed2001

[Genetic studies of 13 loci in Guangdong Han population by two multiplex PCR systems and its forensic application].

OBJECTIVE: The genetic studies of 13 short tandem repeats(STRs) loci in two multiplex amplification systems were carried out on Chinese Han population in Guangdong. METHODS: DNA samples from 328 unrelated individuals were screened. The 13 loci were D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, D16S539, TH01, TPOX and CSF1PO. The PCR products were analyzed and genotyped by ABI 377-96 Sequencer. RESULTS: The combined power of discrimination (DP) was 0.999999999999993 and the combined paternity of exclusion(PE) was 99.999%. These 13 loci met the Hardy-Weinberg expectations. CONCLUSION: The two multiplex amplification systems were very useful in forensic case investigation.

Asian People↗
PubMed2001

[Study on the forensic application of ABO genotyping by PCR-RFLP].

OBJECTIVE: The study was carried out on the application of ABO genotyping by PCR-RFLP to forensic purpose. METHODS: The DNA of samples were extracted by Chelex--100 and phenol/chloroform, the PCR products were separated by Native Horizontal PAGE, and detected by silver staining. RESULTS: The PCR amplified fragment length of ABO loci is from 175 to 210 bp, the frequency distribution of six genotypes ranges from 0.0250 to 0.4300, heterozygosity(H) and discriminating power(Dp) is 0.5162 and 0.7111. CONCLUSION: This technique has a good application to the forensic samples such as blood, blood stain, semen stain, hair root, bone tissue and semen from vaginal swabs.

ABO Blood-Group System↗