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Biomedical subjects

B Liu

Publications and source records attributed to B Liu.

At least 163 records · Page 9Linked to original sources
PubMed2001

[Study of the cytotoxity against human hepatocellular carcinoma cells induced by the MAGE-1 gene modified dendritic cells].

OBJECTIVE: To genetically modify dendritic cells (DC) with a tumor associated antigen gene MAGE-1 and to observe in vitro the cytotoxic effect induced by this genetically modified DC against human hepatocellular carcinoma (HCC) cell line SMMC7721, thus giving a primary verification of the possibility of this genetically modified DC to induce specific antitumor immunity against HCC and serving as a new type of vaccine. METHODS: The MAGE-1 gene was inserted into the retrovirus vector LXSN to construct the recombinant retrovirus LMSN. The monocyte-derived DCs were transfected by LMSN and control virus LXSN respectively as well as a third group was set up as non-transfected control. The MAGE-1 gene expression in LMSN transfected DC was identified by Western blot and the in vitro cytotoxities against SMMC7721 induced by three groups of DC were tested by MTT assay. RESULTS: A recombinant retrovirus LMSN containing the tumor rejection antigen gene MAGE-1 was successfully constructed and the MAGE-1 gene expression in LMSN transfected human monocyte-derived DC was induced. The LMSN transfected DC could induce very high lytic activity against SMMC7721 in vitro with the lytic activity of 78.9%+/-3.6%. Nevertheless, the LXSN transfected DC and non-transfected DC only induced relatively lower lytic activity as 34.7%+/-4.3% and 3.9%+/-2.0%, respectively. The difference of the lytic activities between those three groups as statistically significant (P<0.01). CONCLUSIONS: The MAGE-1 gene transfected DC can induce higher in vitro cytotoxicity against SMMC7721, suggesting the possibility of this genetically modified DC to induce specific antitumor activity and to serve as a new type of vaccine for HCC.

Animals↗
PubMed2001

Polyploid formation in cotton is not accompanied by rapid genomic changes.

Recent work has demonstrated that allopolyploid speciation in plants may be associated with non-Mendelian genomic changes in the early generations following polyploid synthesis. To address the question of whether rapid genomic changes also occur in allopolyploid cotton (Gossypium) species, amplified fragment length polymorphism (AFLP) analysis was performed to evaluate nine sets of newly synthesized allotetraploid and allohexaploid plants, their parents, and the selfed progeny from colchicine-doubled synthetics. Using both methylation-sensitive and methylation-insensitive enzymes, the extent of fragment additivity in newly combined genomes was ascertained for a total of approximately 22,000 genomic loci. Fragment additivity was observed in nearly all cases, with the few exceptions most likely reflecting parental heterozygosity or experimental error. In addition, genomic Southern analysis on six sets of synthetic allopolyploids probed with five retrotransposons also revealed complete additivity. Because no alterations were observed using methylation-sensitive isoschizomers, epigenetic changes following polyploid synthesis were also minimal. These indications of genomic additivity and epigenetic stasis during allopolyploid formation provide a contrast to recent evidence from several model plant allopolyploids, most notably wheat and Brassica, where rapid and unexplained genomic changes have been reported. In addition, the data contrast with evidence from repetitive DNAs in Gossypium, some of which are subject to non-Mendelian molecular evolutionary phenomena in extant polyploids. These contrasts indicate polyploid speciation in plants is accompanied by a diverse array of molecular evolutionary phenomena, which will vary among both genomic constituents and taxa.

Alleles↗
PubMed2001

[Studies on association between lipoprotein lipase gene polymorphisms of Pvu II site and hypertriglyceridemics in Chinese].

OBJECTIVE: To explore whether Pvu II restriction fragment length polymorphisms (RFLP) in the lipoprotein lipase(LPL) gene are associated with hypertriglyceridemics (HTG). METHODS: Pvu II restriction fragment length polymorphisms in the lipoprotein lipase gene on a sample of 135 HTG patients and 193 age-matched healthy individuals in Chengdu area were detected with the method of PCR-RFLP. RESULTS: The P+ P+ genotype frequency and P+ allelic frequency of LPL gene for HTG cases are higher than those for control groups (0.460 vs 0.337,P<0.05; 0.689 vs 0.565,P<0.01). The serum levels of TGapoCII, apoCIII, apoE and TG/HDL-C in P+P+ genotype are higher than those in P-P- genotype(P<0.05). CONCLUSION: The results suggest that P+P+ genotype in the lipoprotein lipase gene is associated with susceptibility to hypertriglyceridemics in Chinese population.

Adult↗
PubMed2001

[The therapy effect of improved bilateral tibia lengthening].

OBJECTIVE: To study the therapy effect of improved bilateral tibia lengthening. METHODS: From May 1997 to May 2000, 32 patients (varus knee deformity in 8 cases) with low stature were adopted in this study. Among them, there were 26 females and 6 males, aged from 18 to 45 years old. Operative procedures included: 1. tibia osteotomy 1 cm distal from tibia tuberosity and fibula osteotomy 10 cm proximal from lateral malleolus; 2. fixation of the tibia osteotomy with interlocking nail and locking the proximal nail; 3. fixation of the lengthening apparatus; 4. lengthened bilateral tibia 0.7 mm per day; 5. removed the apparatus and locked the distal nail 2 weeks later after limb lengthening was over. RESULTS: The mean distance of lengthening was 8.5 cm (ranged 3.5 to 12.0 cm), the mean duration of lengthening was 128 days(ranged 53 to 180 days), and the mean time of bone union was 180 days (ranged 120 to 270 days). Followed up for 1 to 3 years, 98% patients felt satisfactory in lengthening, gait and joint movement. CONCLUSION: The improved bilateral tibia lengthening technique is recommended for advantage of short time of bone union, less complication and correcting the varus deformity of knee simultaneously.

Adolescent↗
PubMed2001

Clinical study on treatment of senile vascular dementia by acupuncture.

63 patients with senile vascular dementia were randomly divided into the treatment group (treated by acupuncture) and the control group (treated with piracetam). The authors observed the changes in the score of Hasegawa's dementia scale (HDS), p300, rheoencephalogram, topographic EEG, superoxide dismutase (SOD) activity in erythrocytes, and lipid peroxide (LPO) level in plasma before and after treatment. The statistical data showed that the total effective rate in the treatment group (80.6%) was significantly higher than that in the control group (25%), and the differences in the observed indexes before and after treatment were significant (P < 0.05 or P < 0.01) in the treatment group but not in the control group (P > 0.05), indicating that the acupuncture treatment was superior in immediate therapeutic effect on senile vascular dementia to drug treatment.

Acupuncture Therapy↗
PubMed2001

An analysis of therapeutic effect of drug acupoint application in 209 cases of allergic asthma.

Both therapies of traditional crude herb moxibustion and drug acupoint application were used in 209 cases of allergic asthma to compare their long-term and short-term therapeutic effects and to analyze the relationship between clinic therapeutic effects of both therapies and differential types of the disease. The results showed that the short-term total effective rate in the group of drug acupoint application was higher than that in the group of traditional crude herb moxibustion, the therapeutic effects of drug acupoint application being closely related to differential types. Analysis also shows the best short-term therapeutic effect was in the type of heat in the lung while the poorest effect in the type of deficiency of the kidney-yang.

Acupuncture Points↗
PubMed2001

Femtomolar concentrations of dynorphins protect rat mesencephalic dopaminergic neurons against inflammatory damage.

The hallmark of Parkinson's disease is the death of nigral dopaminergic neurons, and inflammation in the brain has been increasingly associated with the pathogenesis of this neurological disorder. Dynorphins are among the major opioid peptides in the striato-nigral pathway and are important in regulating dopaminergic neuronal activities. However, it is not clear whether dynorphins play a role in the survival of nigral dopaminergic neurons. We have recently demonstrated that lipopolysaccharide (LPS) activates the brain immune cells microglia, in vitro and in vivo, to release neurotoxic factors to degenerate dopaminergic neurons. The purpose of this study was to explore the neuroprotective effect of dynorphins in the inflammation-mediated degeneration of dopaminergic neurons in rat midbrain neuron-glia cultures. LPS-induced neurotoxicity was significantly reduced by treatment with ultra low concentrations (10(-13)--10(-15) M) of the kappa-opioid receptor agonist dynorphin A (1--17) or the receptor binding ineffective [des-Tyr(1)]dynorphin A (2--17), but not by U50488, a synthetic kappa-receptor agonist. The glia-mediated neuroprotective effect of dynorphins was further supported by the finding that femtomolar concentrations of dynorphins did not prevent the killing of dopaminergic neurons by 6-hydroxydopamine. However, ultra low concentrations of dynorphins inhibited LPS-induced production of superoxide. These results suggest a glia-mediated and conventional opioid receptor-unrelated mechanism of action for the neuroprotective effect of ultra low concentrations of dynorphins. Understanding the underlying mechanisms of action should further define the roles of dynorphins in the regulation of dopaminergic neurons and help devise novel strategies to combat neurodegenerative diseases.

Animals↗
PubMed2001

[Degradation of methamidophos by Saccharomyces rouxii WY-3].

A strain of Yeast WY-3 was isolated from wastewater sample. It is capable of utilizing methamidophos as sole nitrogen and phosphorus sources, and also capable of utilizing methylamine, ethylamine and ammonium sulfate as nitrogen sources except nitrate and hydroxylamine. The yeast could grow in medinm containing 60% glucose and was identified as Saccharomyces rouxii WY-3. The strain contains a high active acid phosphatase. The crude enzyme was applied to a plate of polyacrylanide gel for electrophoresis, then activity was detected as white single band. Inhibiting test showed that sodium fluoride could seriously inhibit the activity of acid phosphatase to release phosphorus from methamidophos, wherease it make no effect on deamination of the strain WY-3 from methamidophos. After methamidophos was degraded by strain WY-3, toxity of the pesiticide reduced obviously, and its portion intermediate, methanol and inorganic phosphorus, were deteted.

Biodegradation, Environmental↗
PubMed2001

[Analysis of apoA IV gene VNTR polymorphism in Chinese endogenous hypertriglyceridemics].

OBJECTIVE: To search the variation of apoA IV gene and its relation to endogenous hypertriglyceridemia (HTG) in Chinese population. METHODS: Forty- seven endogenous hypertriglyceridemics and 48 healthy subjects from a population of Chinese Han nationality in Chengdu area were studied using sequencing of apoA IV gene amplified by polymerase chain reaction (PCR). RESULTS: The frequency of (CTGT)(3) allele in Chinese control group was significantly different from that reported in German Caucasians (0.253 vs 0.607, P<0.01) and in Italian Caucasians (0.253 vs 0.522, P<0.01), but not different from that reported in Japanese (0.253 vs 0.262, P>0.05). The frequency of (CTGT)(3) allele showed no significant difference between normal control and HTG groups(0.223 vs 0.281,P>0.05). In the healthy control group, the subjects with genotype 3/3 of VNTR site had a higher serum mean concentration of LDLC as compared to those with genotype 3/4 (3.698 +/- 0.67 mmol/L vs 2.974 +/- 0.54 mmol/L, P<0.05). CONCLUSION: The results suggest that VNTR polymorphism in apoA IV gene is associated with healthy control subjects to some extent in Chinese population.

Adult↗
PubMed2001

[Quantitative assay of metabolic rate of para-aminobenzoic acid combining glycine for the assessment of rabbit liver function].

OBJECTIVE: To evaluate liver function by the assessment of the capacity of glycine combining para-aminobenzoic acid (PABA) to form hippuric acid in rabbits with acute liver injury. METHODS: Thirty rabbits were randomly divided into two groups: experiment group (n=20) received D-galactosamine to be subject to acute liver necrosis, and control group (n=10) received saline as placebo. Serum concentrations of PABA, para-aminohippuric acid (PAHA), para-acetamidobenzoic acid (PAABA), and para-acetamidohippuric acid (PAAHA) were measured by high pressure liquid chromatography (HPLC). RESULTS: Compared with control group, the serum concentrations of PAHA and PAAHA were significantly reduced in experimental group, which were correlated with the degree of liver injury. CONCLUSIONS: The metabolic rate of glycine combining PABA is a sensitive index for quantitative test of liver function and assessment of acute liver necrosis.

4-Aminobenzoic Acid↗
PubMed2001

[Biomechanical properties of arteries in experimental hypotensive rats].

To study the changes of biomechanical properties after arterial remodeling in hypotension, a model of hypotension was established in rats by constricting the abdominal aorta below the orifice of the left renal artery. The change of opening angles of the abdominal aorta, femoral artery and anterior tibial artery, and the compliance of the abdominal aorta were studied. The relationship between the pressure and volume of the abdominal aorta were also observed in vivo. The results show that non-uniformal remodeling of the hypotensive artery induces the reduction of opening angles in the zero-stress state, the C/E rate of the abdominal artery decreases while the compliance increases.

Animals↗
PubMed2001

[Establishment of cord blood stem cell bank and its clinical application].

OBJECTIVE: To establish unrelated cord blood stem cell bank for providing potential grafts for stem cell transplantation in the treatment of some malignant and nonmalignant disorders. METHODS: All cord blood units(CBU) were obtained from full term normal vaginal and Caesarean-section deliveries. Most of RBC was removed from CBU by the hydroxyethyl starch (HES) method. CBUs were cryopreserved in liquid nitrogen using DMSO and LMD as cryoprotectants. For each CBU, automated cell count, manual viability, HLA typing, screening for infectious agents, colony-forming assays and CD34 analysis by FACS were routinely performed. RESULTS: A total of 2,318 CBUs were collected, among which, 1,240 CBUs met all tests and standards. The average volume of collected qualified cord blood was (98.31 +/- 26.95) ml, the average amount of nucleated cells after separation was (1.22 +/- 0.47) x 10(9), and the average recovery percentage of nucleated cells (88.90 +/- 9.65)%. The average viability was (97 +/- 2.61)%, the number of CFU-GM (5.18 +/- 14.35) x 10(5), of BFU-E (10.35 +/- 11.55) x 10(5), and of CFU-GEMM (1.03 +/- 1.47) x 10(5). The average percentage of CD34+ cells after CBU separation was (0.5 +/- 0.32)%. Four units were positive in microbiological culture and 4 units CMV-IgM positive. In 172 patients registeredd for cord blood transplantation in Guangzhou Cord Blood Bank, the percentage of 4/6 HLA antigens matched units was 91.12%. Up to May 2000, 9 units had been used in unrelated cord blood stem cell transplantation and 6 of them were successfully engrafted. CONCLUSION: It suggested that cord blood bank could be useful in transplantation and the establishment of cord blood bank had a good prospect.

Blood Banks↗
PubMed2001

[The mandibular molar-area implantation of screw-typed dental implants].

OBJECTIVE: To study molar area implantation with screw-typed implant based on the specific anatomic properties of inferior alveolar nerve. METHODS: Depending on the degree of alveolar atrophy in mandibular molar area, the direct implantation, the buccal-to mandibular-canal implantation, and the repositioning inferior-alveolar-nerve implantation were employed. During the period of 1992 to 1998, a total of 22 cases of this kind with 45 dental implants were restored. The follow-up period was 5 years. RESULTS: 2 dental implants were lost respectively after 3 months of insertion and after 1 year of restoration. All the 43 others, however, still remained complete osseointegration, with no obvious crestal bone rebesorption and with excellent function. The 5-year accumulating survival rate of dental implants was 96%. CONCLUSIONS: These three surgical techniques, to a large extent, can solve the problems of mandibular molar area implantation. The key to success of each technique is the selection of patient and the selection of surgical project.

Adult↗
PubMed2001

[Expression of nitric oxide synthase-2 in specific cells of human glaucomatous optic nerve head].

OBJECTIVE: To investigate the specific cells expressing nitric oxide synthase-2 (NOS-2) in the optic nerve head of patients with primary open angle glaucoma. METHODS: Double-labeling immunohistochemistry was used for labeling of NOS-2 and one of the specific cell markers. RESULTS: NOS-2 was labeled in the astrocytes. The NOS-2 positive astrocytes were mainly located in the damaged area of nerve fibers. A few arteries had NOS-2 labeling in the endothelial cells. There was no significant labeling of NOS-2 in microglia, vascular smooth muscle cells and pericytes. CONCLUSION: In glaucomatous optic nerve neuropathy, NOS-2 is mainly expressed by astrocytes. Astrocytes may play an important role in the local neurotoxicity of axons of the ganglion cells by producing excessive nitric oxide.

Aged↗
PubMed2001

[Abnormal expression of p53, Ki67 and iNOS in human esophageal carcinoma in situ and pre-malignant lesions].

OBJECTIVE: To investigate alterations in expression of Ki67, p53 and iNOS proteins in esophageal carcinogenesis. METHODS: The expression of Ki67, p53 and iNOS proteins was detected by immunohistochemical staining of 366 endoscopic biopsy specimens of the esophagus collected from high incidence area of esophageal cancer in China. If the intensity of staining was scored as > or = ++, it was regarded as overexpression. RESULTS: The overespression rate of Ki67 was 0 for normal epithelium(NE), 2.7% for mild dysplasia (MD), 11.2% for moderate dysplasia (MoD), 41.2% for severe dysplasia (SD), and 58.8% for carcinoma in-situ(CIS), respectively. That of p53 and iNOS proteins was 0 and 0 for NE, 10.1% and 4.0% for MD, 24.5% and 7.5% for MoD, 39.2% and 2.5% for SD, 48.7% and 1.4% for CIS, respectively. There was significant difference in the expression of Ki67 and p53 between normal epithelium and dysplasia of various degrees and CIS. Overexpression of Ki67 and p53 correlated well with the pathological grading of the lesions. Positive correlation was also found between p53 and Ki67 overexpressions. CONCLUSION: Overexpression of Ki67 and p53, but not iNOS, is associated with carcinogenesis of the esophagus. They are early events in esophageal carcinogenesis and useful biomarkers for early detection.

Carcinoma in Situ↗
PubMed2001

Clinical application of tentorium cerebelli hiatus incision in treatment of severe and most severe brain injuries.

OBJECTIVE: To explore the role of tentorium cerebelli hiatus incision in treating severe and most severe brain injuries complicated by tentorial herniation. METHODS: From July 1994 to July 1999 tentorium cerebelli hiatus incision was done based on intracranial hematoma evacuation and bone flap craniectomy decompression in 70 cases of severe and most severe brain injuries complicated by tentorial herniation. RESULTS: Of the 70 cases, GCS 3-5 was in 23 and GCS 6-8 in 47; satisfactory recovery in 39 cases (55.7%), moderate disability in 12 (17.1%), severe deficit in 6 (8.6%), vegetative survival in 4 (5.7%) and 8 (11.4%) died. CONCLUSIONS: Tentoriun cerebelli incision is helpful in alleviating secondary brain stem injury from tentorial herniation and in reducing the disability and death rate of the patients.

Adolescent↗