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Biomedical subjects

F Liu

Publications and source records attributed to F Liu.

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

[The effect of lactate-buffered peritoneal dialysis fluid in human peritoneal mesothelial cells function].

OBJECTIVE: To investigate the effect of lactate-buffered peritoneal dialysis fluid (L-PDF) on human peritoneal mesothelial cells (HPMC) function. METHODS: Mesothelial cells from human omentum were isolated and cultured in vitro. Proliferation of HPMC was detected by MTT assay. The quantity of interleukin-8 (IL-8) and fibronectin (FN) in culture supernatants was determined by ELISA. Reverse transcription and polymerase chain reaction amplification were used to detect the expression of IL-8 mRNA in HPMC. Total cellular protein in these supernatants was estimated by using Lowry method. RESULTS: L-PDF inhibited proliferation of HPMC in a time-dependent manner. The levels of IL-8 and FN in the supernatants were remarkably high, and expression of IL-8 mRNA was up-regulated in HPMC exposure to L-PDF. During a subsequent recovery period of 48 hours in culture medium containing lipopolysaccharide (LPS, 10 mg/L), enterotoxin of staphylococcus aureus (10 mg/L) or TNFalpha(10 x 10(6) U/L), the levels of FN in the supernatants increased (P < 0.05). The levels of IL-8 also increased in HPMC stimulated with TNFalpha(P < 0.01). CONCLUSION: L-PDF inhibited proliferation of HPMC and increased levels of IL-8 and FN in the HPMC.

Dialysis Solutions↗
PubMed2001

[Effects of erythromycin and fosfomycin on Pseudomonas aeruginosa biofilm in vitro].

OBJECTIVE: To observe the effects on Pseudomonas aeruginosa biofilm of non-antipseudomonal drugs such as erythromycin and fosfomycin. METHODS: Clinical isolates of Pseudomonas aeruginosa in respiratory infection and ATCC27853 were cultivated in TSB-Teflon and NS-Teflon system respectively for biolfilm formation. Biofilm was observed under scanning electronic microscope (SEM). MICs were determined by broth micro-dilution. RESULTS: SEM showed that biofilm of clinical isolate in TSB-Teflon system and ATCC27853 in NS-Teflon system increased as being cultivated for longer in 1, 3 and 7 days. And biofilm formation in the process of cultivating was inhibited by SubMIC of erythromycin and fosfomycin. MICs evaluation suggested that there were synergetic effects against biofilm Pseudomonas aeruginosa when SubMIC of erythromycin and fosfomycin were combined with ceftazidime or levofloxacin in vitro. CONCLUSION: SubMIC of erythromycin and fosfomycin could inhibit Pseudomonas aeruginosa biofilm in vitro.

Anti-Bacterial Agents↗
PubMed2001

[Expression of GM-CSF in patients with pulmonary alveolar proteinosis].

OBJECTIVE: To investigate the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) protein and mRNA in four patients with pulmonary alveolar proteinosis (PAP). METHODS: GM-CSF levels were measured with a commercial ELISA kit. RT-PCR was employed to detect the expression of the GM-CSF mRNA in peripheral blood mononuclear cells (PBMC) and alveolar macrophages. To discover the possible mutations, the entire coding region of the GM-CSF cDNA was sequenced by the Sanger dideoxy-mediated chain termination method. RESULTS: All patients, except for the one with secondary PAP showed no release of GM-CSF either from PBMC or from alveolar macrophages. The expression of the GM-CSF mRNA was normal in all patients, whereas a point mutation at position 382 of the GM-CSF cDNA from "T" to "C" was revealed by cDNA sequencing in one idiopathic PAP patient, which caused a change from isoleucine to threonine in amino acid 117 of the protein. CONCLUSIONS: Decreased GM-CSF production is associated with the pathogenesis of idiopathic PAP. A point mutation of the GM-CSF cDNA may partly contribute to the decreased GM-CSF production.

Adult↗
PubMed2001

[A study on expression of CD44V6 and PCNA in squamous cell carcinomas].

OBJECTIVE: To investigate the expression of cluster of differentiation 44 variant 6 (CD44V6) and proliferating cell nuclear antigen (PCNA) in squamous cell carcinomas (SCC) in eyes. METHOD: Streptavidinbiotin peroxidase complex (SABC) immunohistochemical method was used to study the expression of CD44V6 and PCNA in 35 cases with squamous cell carcinoma in eyes, 20 cases with papilloma, 11 cases with normal eyelid tissue. RESULTS: The CD44V6 positive rate was 62.9% (22/35) in squamous cell carcinomas in eyes, 15.0% (3/20) in papillomas, none in 11 cases with normal eyelid tissue. The positive expression rate of CD44V6 in the malignant group was significantly higher than that in the benign and control group, and the positive expression rate of CD44V6 in cases with metastasis was significantly higher than that without metastasis. PCNA labeling index (PI) in the CD44V6 positive expression of tumors was significantly higher than that in the CD44V6 negative expression of tumors (t = 20.21, P < 0.01). CONCLUSIONS: The over-expression of CD44V6 is correlated with the progress and metastasis of SCC. CD44V6 protein expression is correlated positively with PCNA expression, and the evaluation of both CD44V6 and PCNA is useful for predicting the prognosis.

Biomarkers, Tumor↗
PubMed2001

[Treatment of ion-exchange monosodium glutamate wastewater by yeast].

Two strains of yeasts, Candida halophila and Rhodotorula glutinis, were acquired through screening from ion-exchange monosodium glutamate wastewater (IEMGW) which was characterized by its high contents of COD (40,690 mg/L), NH(4+)-N (16,914 mg/L) and SO(4)2- (18,000 mg/L). The mixture of the two species had a good COD removal performance for treating IEMGW in a pH rang of 4-9. The yeast technology was superior to the conventional activated sludge in terms of COD removal and COD decomposition rate, In a dilution rate range of wastewater from 1:1 to 1:9, a COD removal of 84.5% and an average COD decomposition rate of over 1.0 kg/(kg.d) were obtained under an initial pH of 4.

Candida↗
PubMed2001

[A quantitative pathological study on angiogenesis, vascular endothelial growth factor and inducible nitric oxide synthase in astrocytomas].

OBJECTIVE: To investigate whether the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) are associated with angiogenesis and malignancy of astrocytomas. METHODS: Immunohistochemistry, semiquantitation and image analysis were used to study the expression features of VEGF and iNOS in 61 cases of astrocytomas having follow-up data. Factor VIII related antigen (FVIII RAg) was also analysed in reflecting the epithelial cell amount and the microvessel density. RESULTS: Microvessels in astrocytomas could be divided into seven types. The positive reaction areas and IA values of FVIIIRAg expression in the endothelium were significantly increased with the increase of tumor grade (P < 0.001) and VEGF labeling index (LI) (P < 0.05). The patients with high VEGF LIs (LI >or= 25%) had a poor prognosis. VEGF expression was significantly related to that of iNOS (P < 0.001), i.e., VEGF level was reduced along with the decrease of iNOS reaction. CONCLUSION: Detection of FVIIIRAg could reflect the angiogenesis activities in astrocytomas. VEGF and iNOS could up-regulate each other to promote angiogenesis and are of importance in determining the malignancy degree of astrocytomas.

Astrocytoma↗
PubMed2001

[A century of developmental history of laparoscopic surgery].

Till the year 2001, the development of laparoscopic surgery will have gone through a total of one hundred years. Laparoscopic surgery has made a great progress during the last more than a decade. In retrospect its history, the development of laparoscopic surgery underwent three main eras, viz. diagnostic laparoscopy, operative laparoscopy and the modern laparoscopy era. Although the laparoscopic technology started rather late in China, it develops very quickly. Along with the development of high -- tech, laparoscopic surgery will have a promising future.

History, 20th Century↗
PubMed2001

[The inhibitory effect of decomposed Chinese traditional medicine Chaihu on Coxsackie B virus(CVB3m) replication and its influence on cell activity].

OBJECTIVE: To study the anti-Coxsackie B virus (CVB3m) action of Chaihu(XCT) and its decomposed herb soups No.1 and No.2 in vitro, and also their protective effect on cells. METHODS: The anti CVB3m and cell protection effects of XCT and its decomposed herb soups No.1 and No.2 were observed by the methods of micro-cell culture and neutral red ingestion, taking cytopathic effect and cell activity as judgments of medicine toxicity and virus replication. RESULTS: The non-toxic concentrations of XCTand its decomposed herb soups No.1 and No.2 had no apparent influence on HeLa cell activity, on the contrary, in certain range of concentrations, they could promote cell growth and cell activity. In therapeutic cell group, XCT and its decomposed herb soups No.1 and No.2 all had apparent inhibitory effect on CVB3m replication, especially the decomposed No.1 showing an inhibitory rate of 107.6%. Under the same decomposed No.1 concentration(1.5 mg/ml), the viral inhibitory rate of the preventive therapeutic cell group was much higher than that of the therapeutic cell group, reaching as high as 128.1%. In virus adsorbed cell group, the CVB3m was also obviously inhibited by the XCT and decomposed No.1 and No.2. CONCLUSIONS: By comparing the effects on cell protection and virus replication of XCT and its decomposed herb soups No.1 and No.2, it identifies that XCT can protect cells against virus infection and directly kill the CVB3m, this Chinese herb medicine may be applied clinically for preventing and curing of viral myocarditis.

Antiviral Agents↗
PubMed2001

[Expression of type I collagen mRNA in rat molar periodontal ligament under normal bite force].

OBJECTIVE: The main component of the periodontal ligament(PDL) is collagen fiber, especially type I collagen, and collagen plays an important role in PDL. The aim of this study is to observe the expression of rat PDL mRNA under normal bite force and to investigate the molecular mechanisms of these changes in type I collagen mRNA. METHODS: 40 male Wistar rats were used, and animals were intra-cardiac perfused with a solution of 4% polyformaldehyde under anesthesia. Dissected mandibles were immersed in the same fixation for 6 hours and subsequently decalcified in EDTA. The demineralized specimens were embedded in paraffin and cut into slices with thickness 5 microns. The probe was synthesized and labeled with digoxigenin. Expression of type I collagen mRNA was measured by using in situ hybridization(ISH). RESULTS: Under the normal bite force, the mRNA expression of type I collagen was very strong on the whole, including the alveolar bone side, the root side and the area between them. Positive signals were located mainly in the cytoplasm and some in the nuclei. But the mRNA expression of type I collagen still had spatial characteristics. The signals in some fibroblasts were apparently stronger than those in other fibroblasts in the apical 1/3 fragment of the roots. The signal of type I collagen mRNA was strong near the root sides. The expression signal on the proximal alveolar walls was strong, however, on the distal alveolar wall, there was no expression. CONCLUSION: The expression of type I collagen mRNA is closely related with bite force.

Animals↗
PubMed2001

[Surface stress analysis of distal extension removable partial denture retained with two types of semi-precision attachments].

OBJECTIVE: The aims of this study are to analyze the surface stress of the periodontal supporting bone of the bilateral distol extension removable partial denture which is retained by using intra-coronal or extra-coronal semi-precision attachment, and to characterize the biomechanics of these two designs by using a strain gauge. METHODS: A fresh human mandible specimen with 76|67 missing and six bilateral partial removable denture retained with six semi-precision attachments were made, including three attachments with intra-coronal studs and three attachments with extra-coronal vertical bars. A total of six 45 degrees rosette strain gauges were bonded at six prepared points on the surface of the mandible to measure the surface stress, including the middle point between 76 of the buccal edentulous alveolar crest area under the denture base verge(point 1), the distal buccal cervix of 5 (point 2), the buccal apical area of 5 (point 3), the buccal middle area of 34 roots (point 4, 5), the lingual middle area of 5 root (point 6). The static loads of 14N, 28N and 42N were applied vertically, buccally 45 degrees, lingually 45 degrees at the middle point of the 6|6 occlusal surface. The micro-strain was recorded, and the maximal/minimal principle stresses were calculated for each RPD and each point. The stress characteristics of these two types of attachments were compared and analyzed. RESULTS: In most situations, the stress of these two semi-precision attachments showed significant differences. The vertical load: The stress values of these intra-coronal and extra-coronal attachments at points 1, 2, 3, 4, 6 differed significantly(P < 0.05), including points 1, 2, (sigma intra < sigma extra) and points 3, 4, 6(sigma intra > sigma extra). Buccal loads: The stress values of these intra-coronal and extra-coronal attachments at points 1, 2, 3, 4, 5 differed significantly(P < 0.05), including points 1, 2(sigma intra < sigma extra) and points 3, 4, 5(sigma intra > sigma extra). Lingual loads: The stress values of these intra-coronal and extra-coronal attachments at points 2, 3, 4, 6 differed significantly (P < 0.05, sigma intra > sigma extra). The intra-coronal attachment generally produced higher stress at the site of the alveolar bone around the abutment than the extra-coronal attachment, but extra-coronal attachment produced higher stress at the edentulous alveolar crest and the distal cervical alveolar bone of the distal abutment than the intra-coronal attachment. CONCLUSION: The intra-coronal attachment is suggested to be applied in some cases that the periodontal condition of distal abutment was good, and the extra-coronal attachment is suggested to be used in some cases that the condition of the edentulous alveolar crest is fairly good, while the periodontal condition of the distal abutment was relatively weak.

Adult↗
PubMed2001

[Primary restoration for congenital malformation of external and middle ear].

OBJECTIVE: To promote the hearing, improve the appearance, shorten the therapeutic course in congenital malformation of external and middle ear, the program of primary restoration has been designed. METHOD: Under general or local anaesthesia a Z-shaped incision is made in skin. After turn up the flap A (defective ear) and flap B(retroauricular skin), a periosteal flap C with pedicle in front is made and elevated from mastoid. Then made frameworklize on mastoid and perform tympanoplasty. Once the myringograft is put properly the flap C is turn into the mastoidal cavity to serve as the lining of anterior wall. Flap A is sutured with the edge of retroauricular incision to serve as the lower part of new auricle. Then use the flap B to wrap a siliceous frame to make the upper part of new auricle. Finally, the naked walls of mastoidal cavity are lined with free skin graft and the cavity is packed with vaseline gauze for two weeks. RESULT: Two cases of congenital malformation of external and middle ear were treated with the procedure mentioned above and were followed up for one and 3 years respectively. Both effects of shape and hearing were good. CONCLUSION: The primary restoration for congenital malformation of external and middle ear designed by the authors is an excellent method worthy to be recommended.

Adolescent↗
PubMed2001

[Research of drug resistance and detection of methicillin-resistant Staphylococcus aureus in chronic maxillary sinusitis].

OBJECTIVE: To investigate the detection method of methicillin-resistant staphylococcus aureus (MRSA) in chronic maxillary sinusitis and the situation of drug resistance to some common antibiotics. METHOD: Using multiplex polymerase chain reaction technique to detect the drug resistant gene (mecA) of MRSA and specific gene (femA) of staphylococcus aureus at the same time. Drug resistant tests were performed with disk diffusion (K-B) method. RESULT: femA is a specific gene of staphylococcus aureus, the detective ratio of mecA in MRSA is 96.2% (51/53). Vancomycin is the only antibiotic which is sensitive to MRSA, while others are not. CONCLUSION: MRSA can be rapidly and specifically identified with multiplex PCR. There are drug resistance to many antibiotic drugs for MRSA.

Adolescent↗
PubMed2001

[Clonning and identification of the gene encoding specific IgE antibody-related antigen of Schistosoma japonicum].

OBJECTIVE: To obtain the gene encoding specific IgE-related antigen of Schistosoma japonicum from the cDNA library of adult Schistosoma japonicum. METHODS: The pooled sera from 15 individuals with high levels of specific IgE antibody against SWAP were absorbed with Protein-G and used for screening of IgE-related antigen from the adult worm cDNA library of Schistosoma japonicum. The inserted cDNA was amplified by PCR and sequenced. According to the first reading frame of the sequence, a pair of new probes, in which EcoR I and Not I sites were incorporated respectively, were designed and used to amplify the target gene. Then, the gene was cloned into vector pGEM-T and subcloned into expression vector pGEX-6p-1. The fusion protein was expressed, analysed by SDS-PAGE and identified by Western blotting with the specific IgE antibody, respectively. RESULTS: The inserted cDNA fragment from the positive clone was about 1,200 bp, with the ORF of 507 bp which encoded 169 amino acids. The deduced molecular weight of the recombinant protein was 19.3 kDa. The homology between the target gene (Sj43B) and other known DNA sequences was less than 40%. The fusion protein expressed by the recombinant vector pGEX-6p-1/Sj43B could be recognized by schistosome specific IgE antibody. CONCLUSION: Sj43B may encode the specific IgE-related antigen of Schistosoma japonicum. The successful construction of recombinant plasmid pGEX-6p-1/Sj43B lay the groundwork for further studies on immunological characteristics and protection immunity of the recombinant protein.

Animals↗
PubMed2001

[The design of detection circuit for DNA biosensor].

The paper describes the design of a quartz crystal sensor for the detection of DNA hybridization reaction. With the ssDNA as probe on the electrode surface, we can detect the frequency change and show it on the computer display. The design is capable of real time monitoring for frequency change of DNA hybridization reaction.

Biosensing Techniques↗
PubMed2001

[Studies on in-vivo process of the enantiomers of nicardipine in rabbit by coupled chiral and achiral HPLC].

AIM: To study the differences of the pharmacokinetics and tissue distribution of two enantiomers of nicardipine in the rabbit. METHODS: Biological samples were diluted by 1 mol.L-1 NaOH solution and extracted with n-hexane--ethyl acetate (1:1). The concentrations of S-nicardipine and R-nicardipine in samples were determined by coupled achiral C18 column (150 mm x 4.6 mm, 5 microns) and chiral OJ column (250 mm x 4.6 mm, 10 microns) chromatography. RESULTS: The racemic nicardipine and the enantiomers in sample were separated well by the coupled system. The linear range was 55-550 ng.mL-1 for both enantiomers. The within-day and between-days RSD (n = 5) were 5.25% and 8.97%, and the relative recoveries were 99.99% and 97.10% for R- and S-enantiomer, respectively. The mean Tmax, Cmax and AUC values were (2.49 +/- 0.03) h, (134 +/- 2) ng.mL-1 and (1082 +/- 32) ng.mL-1.h for S-nicardipine and (1.24 +/- 0.05) h, (109 +/- 2) ng.mL-1 and (778 +/- 22) ng.mL-1.h for R-nicardipine. The concentration of S-nicardipine were generally higher than that of R-nicardipine in main target tissues and cells. CONCLUSION: There were significant differences between the two enantiomers of nicardipine in rabbit in pharmacokinetics and tissue distribution.

Animals↗
PubMed2001

[Studies on the chemical compound of volatile oils from various species of Citrus grandis].

The volatile oils in Citrus grandis from various species were compared by GC-MS. The results showed that the content of volatile oil from Citrus grandis and Citrus grandis (L.) Osbek var. tomentosa Hort. was from 0.7% to 0.9%. Over 30 chemical compounds were identified from the volatile oils and the types of the compounds were almost the same. But gamma-terpinen could not be identified from Citrus grandis which was rich in Citrus gransis (L.) Osbeck var. tomentosa Hort.

Citrus↗
PubMed2001

[Effect of decreased bite force on the temporal and spatial expression of type I collagen mRNA in rat molar periodontal ligament].

OBJECTIVE: The aim of this study was to observe the effect of decreased bite force on type I collagen mRNA in periodontal ligament (PDL) and probe into the molecular mechanism of the change in type I collagen mRNA. METHODS: Animal models were established by extracting left maxillary molars of rats. In situ hybridization was applied. RESULTS: The results showed that under decreased bite force, the expression level of type I collagen mRNA decreased at the sixth hour (49.7 +/- 11.1) (P < 0.05), reached the nadir on the second day (23.7 +/- 8.6), began to get over on the third day (43.1 +/- 10.3), and reached a relatively high level at the second week(56.3 +/- 9.8), but it was still lower than that of the normal bite force group (91.4 +/- 16.0)(P < 0.05); the expression of type I collagen mRNA near the cementum was higher than that near the alveolar bone. CONCLUSION: These results indicate that the expression level of type I collagen mRNA is closely related to bite force.

Animals↗