Biomedical subjects

H Liu

Publications and source records attributed to H Liu.

At least 289 records · Page 16Linked to original sources

PubMed2001

[Effects of ANSON NANOTECH on the healing of cutaneous chronic wounds].

OBJECTIVE: To observe the effects of ANSON NANOTECH on the healing of cutaneous chronic wounds. METHODS: Thirty-four cases with 44 wounds were locally treated with ANSON NANOTECH in the wounds after debridement. Among them, there were 15 cases with traumatic ulcer (23 wounds), 9 cases with pressure ulcer(11 wounds), 5 cases with diabetes ulcer, and 5 cases with radiation ulcer. The healing time of wounds was used to evaluate the treatment results. RESULTS: The healing time in all of chronic wounds were accelerated. All wounds from trauma, diabetes and pressure were healed within 4 weeks and another 2 wounds from radiation injuries were healed over 4 weeks. The healing rate within 4 weeks was 95.5%. CONCLUSION: The results indicate that ANSON NANOTECH can accelerate the healing of chronic wounds. The mechanism probably include sterilization, improvement of local microcirculation, promotion of cell growth, and so on.

Adolescent↗

PubMed2001

[Composting process of municipal solid waste with high effective complex microbial community].

The effects of high effective complex microbial community (MECMC) in a combination composting process of municipal solid waste (MSW) and sludge were examined through inspecting biomass, temperature, organic matter, the carbon, nitrogen ration (C/N). Composting was performed under such conditions: The ratio of MSW:sewage:sawdust:composting of 45:25:15:15 (W/W) and organic matter of 60%, total N of 1.4%, total P of 0.69%, total K of 1.25%, original moisture of 58.5%, original ratio of C/N of 30, aration flow of 0.8 L/min.kg(volatile organic matter). The rates of adding HECMC to treatment 1, treatment 2 and treatment 3 were 2%, 3%, 5% respectively. Control experiment added 3% inactive HECMC. The day of MSW and sludge mature in control experiment, treatment 1, treatment 2 and treatment 3 were 30, 24, 18 and 12, respectivly. This indicated HECMC were effective to compose organic matter and speedup composting change into humus. There are many active bacteria in composting which are favorable for soil.

Bacteria↗

PubMed2001

[Acidity and acid buffering capacity of aerosols during sand-dust storm weather in Beijing].

In the spring of 2000, there were 12 sand-dust storms in Beijing. 2 sand-dust storms were experienced in time and mass concentrations, elementary concentrations acidity and acidic buffering capacity of TSP(Total Suspended Particulate, < 100 microns) and PM10(Inhalable particulate, < 10 microns) were sampled and analyzed. Results showed that pollution level of aerosols was extremely high. However, the acidity of aerosols was relatively low and the aerosols had very strong acid buffering capacity for acidification. Therefore, the aerosols brought about by the sand-dust storms could avoid the occurrence of acidic precipitation to some extent.

Acids↗

PubMed2001

[Effect of calcium and temperature on adhesion of K-ras transformed rat lung cells].

OBJECTIVE: To investigate the effect of calcium and temperature on cancerous cell adhesion. METHODS: K-ras transformed rat lung cells (KNRL cels) were used as experimental group, and normal rat lung cells (NRL cells) as normal control. The cells were cultured under the condition of implementation with Ca2+ and at 4 degrees C, 37 degrees C and 41 degrees C, and without Ca+2 at 37 degrees C. Cell adhesion and aggregation were examined. RESULTS: The average value of adhesive ability (Nt/N0) of KNRL cells was 0.81 +/- 0.15 at 37 degrees C, without CA2+ and 0.60 +/- 0.14, with Ca2+ (P = 0.041). The value was 0.53 +/- 0.12 at 41 degrees C, significantly lower than that at 37 degrees C (P = 0.046). CONCLUSION: Appropriate increase of Ca2+ and high temperature will strengthen the adhesive ability of tumor cells.

Animals↗

PubMed2001

[A preliminary study on translocation of the immunoglobulin heavy chain gene in KM3 myeloma cell line].

OBJECTIVE: To identify the IgH translocation in KM3 myeloma cell line established from a Chinese patients. METHODS: Southern blotting was performed with dig-labeled probes specific for IgH switch regions to identify and distinguish IgH switch recombination events. RESULTS: Besides a 10.0 kb Hind III fragment being able to hybridize with both 5' S mu and 3' S mu probes as that in placenta genome DNA. There was a 5.6 kb Hind III fragment in KM3 genome DNA could only hybridize with the 3' S mu probe. CONCLUSION: There was an illegitimate switch recombination fragment containing 3' S mu region in the KM3 myeloma cell line, which was caused by the IgH translocation involving the IgH S mu region.

Blotting, Southern↗

PubMed2001

[Clinicopathological analysis of 6 cases of diffuse panbronchiolitis].

OBJECTIVE: To study the clinical and pathological characteristics of diffuse panbronchiolitis (DPB). METHODS: Clinical history of six cases of DPB and their pathological slides were studied and analyzed. RESULTS: Diffuse panbronchiolitis was characterized by chronic recurrent nasosinusitis and pulmonary infection and respiratory bronchiolitis. Pathologically, all layers of the respiratory bronchiole walls were involved. Prominent chronic inflammation with lymphocytes, plasma cells and histiocytes infiltration was noted in all cases. In the lumens of the bronchioles, PMN or mucus could be identified. The chronic inflammatory cell infiltration also contained numerous foamy macrophages within the walls of the small bronchioles and in the stroma of the lung as well. Among the 6 cases of DPB, two cases were associated with thymoma. CONCLUSIONS: DPB is a distinct clinicopathological entity. Open lung biopsy or thorocoscopic biopsy is necessary for the correct diagnosis of clinical atypical DPB cases.

Adolescent↗

PubMed2001

[Phacoemulsification and intraocular lens implantation in patients with chronic renal failure and cataract].

OBJECTIVE: To report the experience in treatment of phacoemulsification and intraocular lens implantation and to evaluate its efficacy in patients with chronic renal failure and cataract. METHODS: Twelve patients with chronic renal failure, maintenance dialysis and cataract were treated with phacoemulsification and intraocular lens implantation in 1998-1999. The original disease of renal failure was non-diabetic. The average age was 51 years, and the average time course on dialysis was 6-12 months. All the patients were stable on maintenance dialysis, and the blood pressure was controlled in or near normal range. Before the operation, the administration of heparin was stopped, and the hemostatic drug was applied. RESULTS: All the procedures were performed on 23 eyes these patients without any complications. The naked visual acuity after operation improved significantly in comparison with that before the operation. At the postoperative one month of follow-up, the visual acuity of 52% of the surgical eyes was above 1.0. CONCLUSION: Phacoemulsification and intraocular lens implantation is effective and safe in chronic renal failure patients with cataract.

Adult↗

PubMed2001

Anti-human platelet tetraspanin (CD9) monoclonal antibodies induce platelet integrin alpha IIb beta 3 activation in a Fc receptor-independent fashion.

OBJECTIVES: To characterize the activation of platelet integrin alpha IIb beta 3 induced by two anti-human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action. METHODS: Using 125I-labeled human fibrinogen (Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured. RESULTS: HI117 and SJ9A4 (10 micrograms/ml and 20 micrograms/ml) induced specific Fg binding to human platelets, suggesting that the two mAbs evoked activation of platelet integrin alpha IIb beta 3. Further study indicated that HI117 and SJ9A4 induced integrin alpha IIb beta 3 activation independent of platelet Fc-receptors, and that HI117 and SJ9A4-induced integrin alpha IIb beta 3 activation was inhibited by pretreatment of platelets with sphingosine, aspirin, apyrase, and/or PGI2. CONCLUSIONS: Anti-platelet tetraspanin (CD9) mAbs, HI117 and SJ9A4, can induce platelet integrin alpha IIb beta 3 activation independent of Fc-receptors. Three signaling pathways, namely thromboxane, secreted ADP, and cAMP pathways, may be involved in the process, with protein kinase C activation presumably being the common step of the three pathways.

Antibodies, Monoclonal↗

PubMed2001

ATP sensitive K+ channel may be involved in the protective effects of preconditioning in isolated guinea pig cardiomyocytes.

OBJECTIVE: To develop a cellular model of preconditioning by a brief period of hypoxia in isolated guinea pig cardiomyocytes and to determine whether or not an ATP sensitive K+ (KATP) channel is involved in ischemic preconditioning. METHODS: Single myocytes were isolated from the ventricle of adult guinea pigs. The experimental chamber allowed the cells to be exposed to low O2 pressure. During hypoxic preconditioning, the cells were equilibrated with normaxic solution for 10 minutes and then exposed to hypoxia for 5 minutes, followed by 10 minutes of reoxygenation. The cells were then subjected to 20-180 minutes of hypoxia and reoxygenation. Ionic currents were studied with the patch clamp technique in whole-cell and cell-attached configurations. RESULTS: A 5-minute hypoxic preconditioning offered a significant protection from cell injury in subsequent hypoxia-reoxygenation. After a latency of more than 15 minutes, hypoxia induced a time-independent outward K+ current which could be blocked by 5 mumol/L glibenclamide. At 10 mV, the current increased from 78 +/- 15 pA to 1581 +/- 153 pA (P < 0.01, n = 18). However, the latency to develop KATP channel currents (IKATP) was greatly shortened in preconditioned cells, and the current was increased acceleratively. At 10 mV, the current more than 4 nA was recorded in preconditioning cells. In the single channel recordings, the time interval from the first channel opening to maximum opening was also markedly abbreviated in preconditioned cells. CONCLUSION: Isolated guinea pig cardiomyocytes can be preconditioned with a brief period of hypoxia. This hypoxic preconditioning may modify the KATP channel, and make the channel open more readily during the second hypoxia.

Adenosine Triphosphate↗

PubMed2001

Alterations in myosin heavy chain isoform gene expression during the transition from compensatory hypertrophy to congestive heart failure in rats.

OBJECTIVE: To explore the molecular mechanism underlying the decreased velocity of tension rise in rat myocardium during congestive heart failure (CHF) and left ventricular hypertrophy (LVH) induced by aortic stenosis. METHODS: The maximum velocity of tension rise (+dT/dtmax) was measured in left ventricular papillary muscle and the mRNA level of myosin heavy chain (MHC) isoforms in the left ventricle were detected by Northern blot analysis. RESULTS: The value of +dT/dtmax in CHF and LVH group were 64.17% and 37.15% lower than sham-operated controls (Sham) (P < 0.01); values in the CHF group were 42.99% lower than that of LVH (P < 0.01). The level of alpha-MHC mRNA in LVH was not different from that of the Sham (P > 0.05), but decreased significantly in CHF to 42.3% of Sham and 56.1% of LVH (P < 0.01). The level of beta-MHC mRNA was up-regulated by 88.3% (P < 0.01) in LVH compared with Sham and the level of beta-MHC in CHF was 1.5-fold and 3.7-fold higher than that in LVH and Sham respectively (P < 0.01). The ratio of alpha-MHC/beta-MHC mRNA in LVH and CHF decreased to 42.4% and 9.8% respectively of the value in Sham (P < 0.01). Correlation between alpha-MHC/beta-MHC mRNA level and +dT/dtmax was analyzed which showed that these values were positively correlated with a correlation coefficient of 0.875 (P < 0.01). CONCLUSION: The decreased ratio of alpha-MHC/beta-MHC mRNA was the major molecular mechanism underlying the decreased +dT/dtmax in CHF and LVH myocardium. The decreased ratio of alpha-MHC/beta-MHC mRNA in LVH was mainly due to the up regulation of beta-MHC mRNA while in CHF both down regulation of alpha-MHC and up regulation of beta-MHC were involved.

Analysis of Variance↗

PubMed2001

Analysis of hypermutation of the 5' noncoding region in the BCL-6 gene.

OBJECTIVE: To investigate BCL-6 gene mutations in Chinese populations with B-cell non-Hodgkin's lymphoma. METHODS: Polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) and direct DNA sequencing were used to identify mutations in the 5' noncoding region of the BCL-6 gene in a total of 40 cases of diffuse large-cell lymphoma (DLCL) and follicular lymphoma (FL). RESULTS: Nine cases were found to have base substitutions. The incidence of BCL-6 gene mutation and the frequency of single-base changes were approximately 25.7% and (0.56-1.10) x 10(-2)/bp, respectively. CONCLUSIONS: The 5' regulatory region of the BCL-6 gene undergoes frequent somatic hypermutation during lymphomagenesis and the identification of BCL-6 gene hypermutations provides a molecular marker for confirmatory diagnosis of B-NHL.

5' Flanking Region↗

PubMed2001

Protective effect of human CD40-Ig fusion protein in a murine model of acute graft-versus-host disease.

OBJECTIVE: To investigate the protective effects of blocking CD40/CD40L interactions with human CD40-Ig fusion protein in a murine graft-versus-host disease model. METHODS: Human CD40 gene extracellular region was inserted into plasmid pIG1, which contains genomic human IgG1 Fc gene. A transient vector containing CD40-Fc fusion gene was transfected into COS-7 cells. The CD40-Ig fusion protein was detected through enzyme-linked immunosorbent assay (ELISA). A constitutive vector was also generated by ligating the CD40-Fc fusion gene into pcDNA3.1 and transfecting it into CHO cells. CD40-Ig was purified by protein A affinity chromatography. SDS-PAGE, Western blot and ligand binding assay were used to identify the qualities of CD40-Ig. Murine acute graft-versus-host disease (GVHD) was induced by intravenous injection of C57BL/6J (H-2b) spleen cells into sub-lethally irradiated BALB/c (H-2d) mice. Protective effects against murine graft-versus-host disease by in vivo administration of CD40-Ig were evaluated. RESULTS: Mammalian expression vectors pIG/40Ig and p3.1/40Ig were constructed as described above. Chimeric proteins were expressed in COS-7 and CHO cell culture supernatant and confirmed by ELISA and Western blot. SDS-PAGE showed that fusion proteins had a disulfide-bonded dimeric structure and existed as homodimer. Purified CD40-Ig could bind to CD40L. In vivo administration of CD40-Ig could prevent the development of GVHD and significantly prolong the mean survival time of mice with graft-versus-host disease. CONCLUSIONS: These results demonstrate that CD40/CD40L interactions play an important role in the pathogenesis of graft-versus-host disease and suggest clinical potential for CD40-Ig in the prevention and treatment of human graft-versus-host disease.

Acute Disease↗

PubMed2001

Lack of correlation of vacA genotype, cagA gene of Helicobacter pylori and their expression products with various gastroduodenal diseases.

OBJECTIVE: To investigate the correlation among vacA genotypes, cagA gene, VacA, serum CagA antibodies of Helicobacter pylori (H. pylori) and gastroduodenal diseases. METHODS: vacA genotypes and cagA gene of 62 H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were tested by polymerase chain reaction, and Hela cell assay for VacA activity in vitro. Serum CagA antibodies were measured by EIA method in the same patients. RESULTS: All 62 H. pylori strains possessed the vacA gene and vacA genotypes of all strains were type s1a/m2. Total positive rate of cagA gene was 56.45%; the positive rates of cagA gene of H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were 55.56%, 54.17% and 63.64%, respectively (P > 0.05). The total positive rate of VacA was 37.10%; the positive rates of VacA produced by H. pylori strains isolated from patients with chronic gastritis, peptic ulcer and gastric cancer were 33.33%, 29.17% and 63.64%, respectively (P > 0.05). The positive rates of CagA antibodies in patients with chronic gastritis, peptic ulcer and gastric cancer were 70.37%, 79.17% and 40.00%, respectively (P > 0.05). The total positive rate of CagA antibodies was 68.85%. CONCLUSION: There was no correlation among cagA gene and vacA genotypes of H. pylori, VacA, serum CagA antibodies and various gastroduodenal diseases.

Antibodies, Bacterial↗

PubMed2001

[Distal intramural spread of rectal cancer studied on large slices].

OBJECTIVE: To study the length of distal intramural spread of rectal cancers, and provide evidence for anal-preserving operations. METHODS: Specimens of ninety-eight patients with rectal cancers who had been operated from August, 1996 to October, 1997, were collected and their large pathologic slices examined. The length of intramural spread distal to rectal cancers was measured under light microscope. The actual length of spread in live conditions was estimated according to equal proportional shrinkage. RESULTS: In 48 of the 98 patients, distal intramural spread of the tumor was observed. The length of spread varied from 0.1 cm to 2.5 cm. In 77% of the 48 patients, the length of tumor spread was < 0.5 cm. In only 5 patients was the distance of spread > or = 1.0 cm. Four different ways of tumor invasion were observed: contiguous, lymphatic, neural and venous invasion. Distal intramural spread could be via mucosa, submucosa, inner circular muscular layer, outer longitudinal muscular layer or serosa, either separately or concomitantly. CONCLUSION: Distal intramural spread of rectal cancers can be detected in about 1/2 of the specimens examined on large pathologic slice. In most of them the distance of spread is < 0.5 cm. Occasionally it may be > or = 1 cm. To set the edge of resection > or = 3 cm distal to the rectal cancers is relatively safe in anal-preserving operations.

Colorectal Neoplasms↗

PubMed2001

[Expression of nm23 in breast cancer: correlation with distant metastasis and prognosis].

OBJECTIVE: To investigate the relationship between expression of nm23 gene and distant metastasis and prognosis in breast cancer. METHODS: To detect nm23 protein expression in 101 patients with breast cancer by means of immunohistochemistry and nm23 mRNA expression in 68 patients with breast cancer by RT-PCR. RESULTS: Expression of nm23 gene was inversely correlated with distant metastasis and lymph node metastasis. Among 9 patients with negative node but with distant metastasis, 7 had low expression of nm23. In 29 patients with positive nodes but without distant metastasis, 24 had high expression of nm23, while 6 of 6 patients with positive nodes and distant metastasis expressed high levels of nm23 mRNA. CONCLUSION: Expression of nm23 gene, tumor size and status of axillary lymph node are independent prognostic indicators to breast cancer prognosis.

Adult↗

PubMed2001

[Correlation between the biological behavior and invasion potential in three mouse melanoma cell lines].

OBJECTIVE: To study the correlation between biological behavior and invasion potential in three homologous mouse melanoma cell lines (B16, B16F10, B16BL6). METHODS: The invasion potential of melanoma cells was assayed in a Transwell cell culture chamber. Melanin content was determined by the A value (optical density) at 470 nm in spectrophotometry. Tumor cells migration within the 3-D collagen matrix was microscopically recorded with a time-lapse video recorder and computer-assisted cell tracking system. Gelatin zymography was adopted to assay the type IV collagenase secretion. A PCR-based telomeric repeat amplification protocol (TRAP) was used for assaying telomerase activity. RESULTS: B16BL6 and B16F10 cells showed higher invasion potential than B16, but the melanin content in B16F10 was very low. B16F10 and B16BL6 possessed a higher migration ability, secreting much more type IV collagenase than the B16 though without significant difference as discovered in telomerase activity of the three melanomas cell lines. CONCLUSION: Invasion capability of mouse melanoma is closely correlated to tumor cells migration ability and secretion of type IV collagenase. Melanin content and telomerase activity are not related to the invasion ability of mouse melanoma cells.

Animals↗

PubMed2001

[Surgical management for colon cancer complicated with acute obstruction].

OBJECTIVE: To evaluate the feasibility of tumor resection and stage-I anastomosis for colon cancer complicated with acute obstruction. METHODS: Seventeen colon cancer patients complicated with acute obstruction admitted from 1994-1998 into our hospital, together with 1,872 cases collected from 40 reports published in the same interval in China, a total of 1,889 cases were analyzed as to the results of their surgical management. RESULTS: In the whole group, there was an incidence of 3.1% anastomotic leak, 6.6% wound infection and 1.1% pulmonary infection. Ninety-three patients died of operation with an operation mortality of 4.9%. Postoperative 5-year survival rate was 26.0%-48.0% in patients with stage-I operation. It was 20.0%-38.0% in staged operation. CONCLUSION: Tumor resection with stage-I anastomosis for colon cancer complicated with acute obstruction is acceptable giving relatively satisfactory results. Technique, bowel cleansing during the operation, rational use of antibiotics and adherence to proper indications are crucial for stage-I operation.

Acute Disease↗

PubMed2001

[Serum leptin level in hemodialysis patients and its relation to their nutritional status].

OBJECTIVE: To investigate the leptin levels of hemodialysis (HD) patients and the relation to their nutritional status. METHODS: Thirty maintenance hemodialysis patients and thirty healthy control subjects were recruited for the study. Blood was drawn after an overnight fast. Serum leptin was measured using a human leptin RIA kit. There were also blood tests to measure BUN, creatinine, serum albumin, transferrin, prealbumin, insulin, cholesterol etc. RESULTS: Mean serum leptin concentration was significantly higher in the HD group than that in the control (P < 0.01). HD group had significantly higher concentrations of BUN, creatinine, serum albumin, transferrin and prealbumin (P < 0.01). Leptin levels in HD patients correlated positively with body mass index (BMI), total systemic flow (TSF), and concentration of insulin (r = 0.53, 0.66, 0.57, respectively, P < 0.01). No significant correlations were observed in HD patients between leptin and BUN or creatinine, or between leptin and nutritional indices. CONCLUSION: Our data suggests that leptin is markedly increased in HD patients. Serum leptin correlates strongly with BMI, TSF and insulin level. No significant correlations were observed in HD patients between leptin and other indices.

Adult↗