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Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 289 records · Page 16Linked to original sources
PubMed2000

Obliterated processus vaginalis diagnosed by intraoperative laparoscopy is unlikely to develop into a clinical hernia.

BACKGROUND: This study was conducted to evaluate if a subsequent inguinal hernia would occur in the contralateral obliterated processus vaginalis shown by intraoperative laparoscopic examination. METHODS: From July, 1993 to February, 1994, 120 patients with a unilateral inguinal hernia were identified as obliterated processus vaginalis by intraoperative laparoscopic examination of the contralateral internal ring when they received unilateral herniorrhaphy. A five-year follow-up of the contralateral side to determine the rate of subsequent inguinal hernia was carried out during an outpatient clinic check-up or by telephone contact. RESULTS: One patient, among the first few patients having laparoscopic examinations, had a subsequent contralateral inguinal hernia. Two patients had hydroceles and each of the operative findings was a communicating hydrocele that could not possibly develop into a clinical hernia. CONCLUSIONS: It is unlikely for an obliterated processus vaginalis indicated by intraoperative laparoscopic examination to become a clinical inguinal hernia.

Adolescent↗
PubMed2000

[Study on hepatitis C virus infection of peripheral blood mononuclear cells in chronic hepatitis C patients].

OBJECTIVE: To demonstrate HCV infection and replication in the peripheral blood mononuclear cells (PBMCs) of hepatitis patients by the methods of molecular biology, immunology and electron microscopy. METHODS: HCV RNA and antigens were detected in the PBMCs of 28 patients with chronic hepatitis C by RT-PCR, Immunohistochemistry and electron microscopy, respectively. RESULTS: The positive rate of HCV RNA and HCV antigens were 77.27% (17/22) and 75.00% (21/28), respectively. Two types of spherical HCV-like particles with diameter of approximately 65 nm and 110 nm were observed in cytoplasmic vesicles by electron microscopy in the PBMCs with high titer of HCV RNA and antigens in 10 patients. The budding and shedding of these particles could also be found in the cytoplasmic vesicles. Immunoelectron microscopy using antibodies against HCV core and NS(3) demonstrated that the particles contained HCV antigens. CONCLUSION: HCV can infect and replicate in the PBMCs of patients with chronic hepatitis C.

Hepacivirus↗
PubMed2000

Effects of carbon tetrachloride-injured hepatocytes on hepatic stellate cell activation and salvianolic acid A preventive action in vitro.

OBJECTIVE: To investigate the effects of carbon tetrachloride (CCl(4))-injured hepatocyte on hepatic stellate cell (HSC) activation, the relation between lipid peroxidation and liver fibrosis, and the action mechanisms of salvianolic acid A (SA-A), one of water soluble components extracted from radix salvia miltiorrhizae, against HSC activation and liver fibrosis. METHODS: The hepatocytes were isolated from the normal rats, incubated with SA-A at different concentrations, respectively, and vitamin E severed as control. At the same time the cells were fumigated with CCl(4) for 24h, and ALT activities in the medium were measured. After the cell medium was changed and cultured for another 24h, the medium was collected as "hepatocyte conditioned medium" (HCM) and measured for malondiadehyde (MDA) content. Then HCM was incubated with primary cultured HSC for 48h, and HSC proliferation, type I collagen gene expression and protein production were observed. RESULTS: ALT activity and MDA content in the hepatocyte medium were increased remarkably after the cell was injured. HCM could obviously promote HSC proliferation, type I collagen mRNA expression and protein production. SA-A could markedly inhibit ALT activity and MDA content in hepatocytes, and decreased collagen gene expression and protein production. CONCLUSION: The secretion from the peroxidative injured hepatocyte could stimulate HSC activation, SA-A could decrease activation by alleviation of hepatocyte peroxidation.

Alanine Transaminase↗
PubMed2000

[Prospective study on the relationship between treatment duration of antithyroid drug and remission rate of Graves' disease].

OBJECTIVE: To compare the potential benefits of 36-month treatment with 6- and 18-month treatment of antithyroid drug in patients with hyperthyroidism due to Graves' disease (GD). METHODS: 183 GD patients were studied prospectively. All patients received methimazole (MMI) at decreasing doses for 6, 18 or 36 months. The relapse rates 18 months after MMI withdrawal were compared between the three therapy groups. RESULTS: The relapse rate 18 months after the discontinuation of treatment was higher in patients treated for 6 months than in those treated for 18 or 36 months. There was no significant difference between 18-month and 36-month treatment groups. At the end of therapy, serum thyroid stimulating antibody (TSAB) and TSH receptor antibody (TRAB) titers were greater in patents treated for 6 months (320 +/- 191 for TSAB and 8.72 +/- 5.23 for TRAB) and 18 months (165 +/- 87 and 4.55 +/- 4.17) than in those treated for 36 months (126 +/- 77 and 2.19 +/- 2.64), but no statistical difference was found between the three groups before MMI treatment. TSAB and TRAB titers were higher in patients who relapsed after discontinuation of MMI (287 +/- 94 and 6.14 +/- 2.37, respectively) compared with those who remained euthyroid through the 18-month follow-up period (144 +/- 61 and 1.97 +/- 1.06). CONCLUSIONS: Negative TSAB or TRAB at the end of antithyroid therapy is a good indicator for a long-term remission after treatment withdrawal. However, treatment duration greater than 18 months does not improve remission rate of GD.

Adolescent↗
PubMed2000

[Suture distraction osteogenesis for closure of cleft palate in the dog: long-term effect and its influence on facial growth].

OBJECTIVE: The purpose of the study was to evaluate the long-term effect and its influence on facial growth of suture distraction osteogenesis for closure of cleft palate. METHOD: 14 Beagle dogs were used in the study. Six of them were in the experimental group, eight served as the control. Direct measurements were taken on dry skulls of the dogs and the data were analysed statistically. RESULTS: The results showed that bony healing at the midline between the two horizontal portions of the palatine bones appeared in all the experimental dogs. There were no significant differences in the variables of facial length and height between the two groups. But the facial width and the distance between the two vertical portions of the palatine bones were significantly less in the experimental dogs than the control. CONCLUSIONS: It is suggested that bony repair of the cleft could be accomplished permanently with the technique of sutural distraction. This technique had no influence on facial length and height growth, but could led to underdevelopment of the width of the face and the respiratory tract of the palatal portion.

Animals↗
PubMed2000

[Effect of eosinophil apoptosis on glucocorticoid-resistant asthma].

OBJECTIVE: To investigate the function of eosinophil apoptosis and regulation of glucocortico steroids on IL-5 and GM-CSF expression in peripheral blood mononuclear cells (PBMCs) in glucocorticoid-resistant asthmatic patients. METHODS: Eosinophils (EOS) and PBMCs isolated from glucocorticoid-sensitive (SS, 15 cases) and resistant (SR, 30 cases) asthmatic subjects were cultured and treated with dexamethasone (DXM) in vitro. Concentrations of IL-5 and GM-CSF were determined by ELISA in the supernatants recovered in sham and DXM treated cells. The rates of EOS apoptosis and Fas antigen expression were documented via flow cytometer in sham, DXM treated and PBMC supernatant treated groups respectively. RESULTS: There were no statistical significant differences of the concentrations of both IL-5 and GM-CSF in sham cultured PBMC supernatants between SS and SR groups [(196 +/- 68) micrograms/L vs. (235 +/- 98) micrograms/L IL-5 (P > 0.05), (325 +/- 110) micrograms/L vs. (356 +/- 131) micrograms/L GM-CSF (P > 0.05); SS versus SR groups, respectively]. There were statistically significant decreases in both IL-5 and GM-CSF after DXM exposure in SS group [(196 +/- 68) micrograms/L vs. (147 +/- 62) micrograms/L IL-5 (P < 0.01); (325 +/- 110) micrograms/L vs. (270 +/- 97) micrograms/L GM-CSF (P < 0.01)]. In contrast, there were no significant differences in both IL-5 and GM-CSF after DXM exposure in SR group. Baseline rates of both EOS apoptosis and Fas antigen expression were statistically significant different between SS and SR groups [(67 +/- 21)% vs. (33 +/- 17)% the rate of EOS apoptosis (P < 0.001); (54 +/- 23)% vs. (27 +/- 15)% the rate of Fas antigen expression (P < 0.001), SS versus SR groups, respectively]. A dramatic increase in EOS apoptosis after DXM exposure was observed in SS group [(67 +/- 21)% vs. (89 +/- 20)% (P < 0.01), baseline vs. DXM exposure, respectively], but there was no significant change in Fas antigen expression. There were no significant changes in both EOS apoptosis and Fas antigen expression in SR group after DXM exposure. CONCLUSIONS: These data suggest that EOS compromised apoptosis might exist and could not be affected by glucocorticoid induction in SR asthma. On the other hand, Th2 cytokine over-expression could not be inhibited by glucocorticoid in SR group in vitro.

Anti-Asthmatic Agents↗
PubMed2000

[Molecular epidemiological study on HIV-1 infection in Shandong Province].

OBJECTIVE: The aim of this study was to understand the distribution of HIV-1 strain subtypes and their variation in Shandong Province and to analyze their source and predict their epidemic trend. METHODS: We collected the whole blood from 25 anti-HIV-1 antibody positive cases and separated the peripheral blood mononuclear cells. The provirus DNA was extracted and amplified by nested-PCR, after which the HIV-1 membrane protein gene (env) C2-V3 region was sequenced and its subtype was analyzed. RESULTS: Among 25 HIV-1 antibody positive cases, 24 HIV-1 env gene fragments were amplified and analyzed.5 subtypes of Group HIV-1 M were identified among these cases,that are subtypes A, B, B', C and E. 13 occupational blood donors were all classified as subtype B' (Thailand B'). A, B, C or E subtypes were discovered in 10 returned laborers working abroad and 1 female spouse of one laborer. CONCLUSIONS: The condition of HIV-1 subtype infection was complicated in Shandong Province. So, it is important to strengthen the surveillance and control of HIV-1 subtype strain infection in high risk populations especially the occupational blood donors and returned laborers working abroad to prevent its spread in Shandong Province.

Adult↗
PubMed2000

[Study on typing of respiratory syncytial viruses].

OBJECTIVE: To determine the epidemiologic patterns of subgroups A and B and genotypes of respiratory syncytial viruses (RSV) during two uncontinuously epidemic years from 1990 to 1991 and 1997 to 1998 in Beijing. METHODS: Nasopharyngeal secretion (NPS) samples of RSV positive or BSV isolates tested by indirect immunofluorescent (IIF) assay were classified into subgroups A and B. Also, isolates of RSV were divided into at least six different lineages, designated NPl-6, by restriction mapping of the N gene. NP l, 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 SHL 1-6 on the basis of the SH gene sequence. SH lineages were closely related to each other and to NP 1-6. Strains of SHL 1,3, and 4 were closely related and belonged to NP2, SHL 2 and 6 to NP4 and SHL5 to NP5. RESULTS: Of 145 RSV NPS samples from the winter 1997 to the spring 1998, 83(57.2%) were subgroup B strains, 62(42.8%) were sub-group A strains, the rate of occurrence of subgroup A to B strains was about 1:1.3. Two of 10 isolates of 1997-1998 offered by viral department of research institute of Pediatrics 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 epidemic were dominant, the proportion of subgroup A to B strains was 4:1. of 10 BSV isolates in 1997-1998, all 2 subgroups 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 subgroups B strains all belonged to NP3. The classification of subgroups A and B deduced from NP patterns was corresponded to the definition of these subgroups by monoclonal antibodies. CONCLUSIONS: These observations confirmed that subgroups A and B or multiple lineages of BSV co-circulated in Beijing, but different genomic 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.

Child↗
PubMed2000

[A serial histological study on suture expansion osteogenesis for cleft palate closure].

OBJECTIVE: The purpose of this study was to know the process of tissue response and regeneration in the palato-maxillary suture under tensile forces. METHODS: Sutural tissue changes after 3, 7, 14, 28, 56 days of suture expansion were examined histologically and fluorescently. RESULTS: It was found that a cyst-like zone appeared in the conjuncture of bony front and sutural connective tissue at the early stage of sutural expansion. Then a great amount of osteoblasts and fibroblasts proliferated. New bone deposited along the septum and the front of the cyst until the new bone front formed and the suture restored its original morphology. CONCLUSIONS: The findings suggested that sutural expansion be a process of bone tissue regeneration and fibrous tissue repair.

Animals↗
PubMed2000

Effects of salvianolic acid-A on rat hepatic stellate cell proliferation and collagen production in culture.

AIM: To investigate the effects of salvionolic acid-A (SA-A), one of main effective components of Salvia miltiorrhiza for its antifibrotic action, on the cell proliferation and collagen production in cultured hepatic stellate cells (HSC). METHODS: HSC were isolated through in situ perfusion of liver with pronase E and collagenase, and gradient centrifugation with Nycodenz. The cultured HSC were incubated with SA-A 0.1-100 mumol/L for 24 h. MTT spectrometric assay and intercellular incorporation of methyl-[3H]thymidine ([3H]TdR) was used to assess the cell proliferation. The amount of collagen was semi-quantified by ponceau staining and image analysis, the amount of type I collagen secretion was measured with ELISA and normalized by the total protein of cell layer. The total RNA was prepared from the control cells and the drug treated cells respectively, and the expression of pro-collagen alpha 2 (I) mRNA was semi-quantitatively analyzed with RT-PCR. RESULTS: SA-A 100 mumol/L showed a little cytotoxity, SA-A 0.1-10 mumol/L did not influence cell morphology, and SA-A 1-100 mumol/L decreased the cell proliferation significantly in a concentration-dependent manner (P < 0.05). SA-A 1, 10, 100 mumol/L decreased the cell collagen deposition by 78.6%, 71.8%, and 61.3% of the control respectively (P < 0.05), and decreased type I collagen secretion to 53.1%, 52.6%, and 49.5% (P < 0.01 or P < 0.05). Both SA-A 1 and 10 mumol/L downregulated procollagen alpha 2 (I) mRNA expression remarkably (P < 0.05). CONCLUSION: SA-A inhibited HSC proliferation and collagen expression. The inhibitory effect on HSC activation is the main mechanism of SA-A action against liver fibrosis.

Animals↗
PubMed2000

[Correlation between endothelin, nitric oxide and microcirculation in super-thinned skin flap in pig].

OBJECTIVE: To investigate the influence of the endothelin (ET) and the nitric oxide (NO) on the microcirculation of a super-thinned skin flap. METHODS: With pig, a super-thinned skin flap, only including subdermal vascular networks, was raised and sutured back on its bed on one flank of each pig, and on the other flank a traditional skin flap was also formed for the controlled group. A laser Doppler Flowmeter was used for evaluation of the blood circulation before and after the operation. The endothelin and the nitric oxide of the flap were examined after certain times of the operation. Furthermore, the necrosis of each flap was decided 7 days after the operation. RESULTS: The ET and NO were significantly increasing after 1 hour of the operation in both of the groups (the peak value of ET at 6 hours and NO at 3 hours after the operation). However, the ET in the super-thinned flap group was significantly lower at 1, 3, 6 hours after the operation, compared with the centrolled group (P < 0.05), but the NO measured meantime was significantly higher than the control (P < 0.05). The blood flow of the super-thinned flap was significantly higher than the control flap separately at 1, 3, 6 hours after the operation (P < 0.01). The survival of the super-thinned flap increased about 35% more than the control. There was a negative correlation existed between the ET and the blood flow, as well as a positive correlation between the NO and the blood flow. CONCLUSION: This study has indicated that the changes of the ET and NO in the flaps, especially in the super-thinned flap, have strongly correlated with their microcirculation. The highter survival rate of the super-thinned flap might owes to the mechanism which the ET in the flap produces less while the NO more, Compared with the traditional skin flap.

Animals↗
PubMed2000

[Response of Capsicum frutescens metapopulation to simulated insect herbivorous behaviors].

Based on the theory of metapopulation, this paper studied the response of different leaf-cutting Capsicum frutescens metapopulation to simulated short-term insect pestes during high temperature period in July. Variance analysis (ANOVA), principal component analysis(PCA) and plant growth analysis were applied. The result shows that C. frutescens had a strong compensatory ability. The number, dry weight and leaf area of old leaves decreased with increasing leaf-cutting, but contrarily for new leaves. The total leaf number did not show any significant difference, but the total area and weight of leaves were significantly different, because of the influence of old leaves. The number, weight and lenght of branches were not significantly different with different treatments, and the number of fruits, flowers and flower buds also showed no significant difference. However, the difference of their dry weights was significant. It is practical to use number indexes, but not dry weight, leaf area and length for plant growth analysis in metapopulation, when the difference of dry weight between modulars is small. It is suggested that a certain degree of herbivory might be beneficial to the growth and fruit yield of C. frutescens during the high temperature period.

Capsicum↗
PubMed2000

[Uptake of particulate lead via gills of goldfish].

This paper studied the uptake of Pb absorbed on suspended gibbsite via gills of goldfish (Carassius auratus). Under conditions of the concentration of the particulate Pb varied while that of free Pb maintained at a constant level, the levels of both Pb and Al in the gills increased with increasing exposed Pb concentration. The increasing rate (slope 0.171) of Pb level in the blood with the Pb level in the gills was lower than that (slope 0.343) of soluble Pb exposure experiment. Partial Pb adhered on the gills did not transfer into blood. The ratio of Pb/Al in the gills was 1-2 orders of magnitude higher than that in the water, and on the microtome section of filament, the gibbsite particles adhered on gill mucus were observed, indicating the bioavailability of the particulate Pb uptake by the gills of goldfish. The major mechanism was: when the absorbed Pb on suspended particles was flowed into gill filaments, it was desorbed on the surface of gills, and then, passively diffused or transferred by carriers via gill cells into flood, and after the particles stayed on the surface of gill filaments for a short time, in company with sloughed mucus, they were released from the gills along with waterflow.

Absorption↗
PubMed2000

[Counteracting effects of intermittent head-up tilt on simulated-weightlessness induced atrophy of anti-gravity muscles].

Objective. To study the efficacy of intermittent + Gz (45 degrees head-up tilt, HUT) exposures in preventing or alleviating atrophic changes in hind limb muscles induced by simulated weightlessness. Method. Male Sprague-Dawley (SD) rats were assigned randomly to one of three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus 6 h/d HUT (SUS + HUT). Muscles examined included soleus (SOL), medial gastrocnemius (correction from grastrocnemius) (MG), lateral gastrocnemius (LG) and extensor digitorum longus (EDL). Sections were treated with an adenosinetriphosphatase (ATPase) stain or alkaline phosphatase stain. The cross-sectional areas (CSA) of fibers, the relative proportion of type I fiber and the ratio of capillaries/fibers (C/F) were measured using Leica image analysis system. Result. Compared with CON, the wet weight of hind limb muscles in SUS were significantly reduced. The changes of wet weight in different groups were various. The C/F ratios of all muscles were significantly reduced. SUS + HUT rats showed significant increases in SOL and MG wet weight, and the relative counter-effects of intermittent HUT were 93.4% and 34.8%, respectively. In SUS + HUT group, the CSA of both type I and II fibers and relative proportion of type I fibers were completely recovered in SOL, and partially recovered in MG, while the counter-effects were much less obvious in the fibers of LG and EDL. However, HUT resulted in a significant recovery of the C/F ratios in all muscles. Conclusion. The present study demonstrated that intermittent HUT is effective in counteracting the atrophy induced by simulated weightlessness. The result that reactivity to HUT varied among different muscles suggests that the intermittent artificial gravity should be complemented with other countermeasures.

Animals↗
PubMed2000

High frequency loss of heterozygosity in the region of the DBH locus in bladder cancer.

OBJECTIVE: To determine the location of a putative tumor suppressor gene (TSG), and evaluate the frequency loss of heterozygosity (LOH) of the long arm of chromosome 9 (9q) in bladder cancer. METHODS: We analyzed 25 patients with bladder cancer for LOH of 9q using 25 high-density microsatellite markers. RESULTS: Twenty-three samples (92%) showed LOH at least at one locus on 9q. We identified that the commonly deleted region were at 9q12-q21, 9q22, and 9q34. The rate of LOH was 44.0%, 22.7%, 22.7%, 16.0%, 12.0% on DBH, D9S15, D9S1815, D9S1831, D9S176 locus, respectively, and was not significantly related with grades and stages of tumor. CONCLUSION: These data suggest that alteration of a TSG at DBH of 9q may play an important role in the development of bladder cancer.

Chromosomes, Human, Pair 9↗
PubMed2000

Kinetic study of eosinophil apoptosis and its relationship to Th2 cytokines in asthmatic murine model.

OBJECTIVE: To investigate the significance and regulatory mechanism of eosinophil apoptosis in asthmatic airway inflammation using an animal models, as well as its relationship to IL-5 and IL-10. METHODS: An animal model of asthma was established by ovalbumin (OVA) sensitizing-challenging BALB/C mice. At seven points in the time course after challenge, bronchoalveolar lavage (BAL) was performed to obtain BAL cells. Levels of two Th2 cytokines, IL-5 and IL-10 were detected by ELISA. A double label technique combining CD15 with CD49d was used to distinguish eosinophils from other cell types. Cell apoptosis was assayed by PI stain using a flow cytometer. RESULTS: Eosinophil apoptosis was identified and a two-phase elevation of apoptosis percentages was observed, although no significant difference was found between average apoptosis in the asthmatic group and that in the control. Analysis of kinetic changes of eosinophil apoptosis and cytokine levels revealed a negative correlation between apoptosis percentages and levels of IL-5, and a closer correlation between apoptosis percentages and the IL-5/IL-10 ratio. Dexamethasone pretreatment markedly reduced IL-5 levels in BAL, elevated eosinophil apoptosis percentages, but had no effect on IL-10 levels. CONCLUSION: Eosinophils underwent apoptosis in asthmatic airways. Equilibrium between IL-5 and IL-10 not only regulated eosinophil infiltration, but also modulated cell apoptosis.

Animals↗
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↗