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Biomedical subjects

C Li

Publications and source records attributed to C Li.

At least 271 records · Page 15Linked to original sources

Early treatment of wounds polluted by sea water.

During construction or training at sea, wounds are commonly seen and irresistibly polluted by sea water. An early and proper treatment of wounds polluted by sea water is very important for wound healing and function recovery of extremities. Some wounds even result in vegetation. In this study, we have reported the treatment results of 132 cases of wounds polluted by sea water admitted from 1985 to 1999.

Accidents, Occupational↗

[Mechanism of multidrug resistance caused by retinoic acid].

OBJECTIVE: To investigate the regulatory mechanism of multidrug resistance(MDR) caused by all-trans retinoic acid (ATRA). METHODS: ATRA and IL-4 were used to treat human hepatoblastoma cell line (HepG2) cells. The proliferative activity, synthesis of alpha fetal protein (AFP), and cell cycle distribution of tumor cells were observed to evaluate the degree of cell differentiation. Flow cytometry and in situ hybridization were used to determine the expressing levels of p53, bcl-2, P-glycoprotein (P-gp) and c-jun and c-myc mRNA. MTT assay was used to evaluate the sensitivity of the tumor cells to chemotherapeutic agents. RESULTS: Both ATRA and IL-4 could induce the differentiation of HepG2 cells. ATRA treatment of the tumor cells led to drug resistance in chemotherapy (resistant factors: 1.6-3.1), and IL-4 increased the sensitivity of the tumor cells to antineoplasic drugs (reversal index: 4-17). The level of P-gp expression in ATRA-treated cells was increased from 54.2% +/- 8.6% up to 98.5% +/- 1.4% (P < 0.01), but IL-4 markedly inhibited expression of P-gp down to 25.4% +/- 7.3% (P < 0.01). Both ATRA and IL-4 treatment could down-regulate c-jun and c-myc mRAN expressions. The level of p53 and bcl-2 expression could be up- or down-regulated by IL-4 treatment but they were unaffected by ATRA treatment. CONCLUSION: Degree of cell differentiation and level of c-jun and c-myc mRNA expression might not be related to change in drug sensitivity by inducing differentiation of HepG2 cells with ATRA and IL-4. Increased expression of P-gp caused by ATRA might be one of the factors up-regulating MDR. p53 (or bcl-2) might be involved in regulating the sensitivity of antineoplastic drugs by inducing differentiation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Combined percutaneous ethanol injection through liver puncture and transcatheter hepatic arterial chemoembolization for hepatocellular carcinoma].

OBJECTIVE: To study the therapeutic effects of transcatheter arterial chemoembolization (TACE) combined with beta-ultrasound guided percutaneous ethanol injection (PEI) at multiple points for hepatocellular carcinoma. METHODS: Eighty-seven patients with hepatocellular carcinoma were divided into two groups: Group A, 45 patients were treated with TACE only, group B, 42 patients were treated with TACE plus PEI. RESULTS: In group A patients, the 1-, 2-, and 3-year survival rates were 66.7%, 41.4%, and 21.4%, respectively. Only 26.1% of cancer specimens showed complete necrosis by pathologic examination in group A. In group B, the 1-, 2-, and 3-year survival rates were 97.1%, 85.71% and 65.71%, respectively, with complete necrosis in 81.8%. CONCLUSION: The therapeutic effects of transcatheter arterial chemoembolization combined with percutaneous multiple point ethanol injection through liver puncture is much better than that of TACE alone.

Administration, Cutaneous↗

[Vitreous surgery for proliferative maculopathy].

OBJECTIVE: To explore the indication of vitrectomy for the treatment of pre-macular proliferative disease, the surgical technique, results and the prevention and treatment of complications. METHODS: Forty-one eyes of 41 cases with different kinds of macular traction or macular pucker, including 12 cases of idiopathic epimacular membrane, 10 cases of macular hole complicated with epimacular membrane and 19 cases of macular pucker after reattachment surgery (no diabetic retinopathy or retinal detachment) were treated with vitreous surgery. The issue of this operation is to find out underlying fissures (an under-bridge) or weakly adherent sites between a membrane and the retina. Using flute-needle, intraocular pick, spade and vitreoretinal forceps, we can separate and peel the proliferative membrane and the posterior cortical vitreous from the retinal surface completely. RESULTS: In 41 cases, epimacular membrane was peeled successfully, and the normal anatomic structure of the macula was restored. Four cases had small amount of hemorrhage in the superficial layer of the retina in and after the operation, and all the other cases did not have any complications, such as retinal tear or detachment. Thirty-eight cases obtained higher visual acuity, and in 3 cases the visual acuity maintained at their pre-operative level. Metamorphopsia was significantly improved, even disappeared. The follow-up period was 3 months to 4 years. CONCLUSIONS: The therapeutic effects of vitreous surgery for treatment of various kinds of proliferative maculopathy are reliable. After the surgery, the visual acuity can be elevated, the symptoms can be ameliorated and the complications can be effectively controlled.

Adult↗

[Preparation of green fluorescent protein retrovirus and its application in mediating gene transfer into retinal pigment epithelial cells].

OBJECTIVE: To determine whether human retinal pigment epithelial (RPE) cells can be infected by retrovirus and modified by retrovirus-mediated gene transfer. METHODS: Recombination retroviral vector pLNCX-GFP (green fluorescent protein, GFP) was generated by inserting 780 bp GFP cDNA fragment into the MCS site of pLNCX. pLNCX-GFP was transfected into ecotropic packaging cell line PhiX-Eco and amphotropic packaging cell line PhiX-Ampho and PA317. Retroviral titer was tested by counting GFP expression of NIH3T3 cells. Then RPE cells were infected by using GFP retrovirus-containing supernatant. RESULTS: GFP was expressed and retrovirus was produced upon pLNCX-GFP being transfected into packaging cell line. The GFP retrovirus was able to infect primary cultured human RPE cells and immortalized RPE cell line. CONCLUSION: The retrovirus can introduce a foreign gene into RPE cells efficiently, thereby it can be used as an important tool to deliver gene into RPE for therapy of fundus diseases.

Cells, Cultured↗

[Using Hsp70 promoter to regulate target gene expression in tumor].

OBJECTIVE: To regulate gene expression in the desired tumor cells both in vitro and in vivo. METHODS: Heat inducible green fluorescent protein (GFP) expression plasmid and adenovirus were built by using different sizes of 5' end regulating sequence from human heat shock protein (Hsp) gene as promoter and GFP cDNA as report gene. GFP expression turned on by heating was observed in the cultured cells and the tumor grown in the dorsal skin window chamber. RESULTS: A 400 bp of Hsp gene 5' end regulating sequence can be activated by heating and it can drive report gene expression effectively both in vitro and in vivo. CONCLUSIONS: Heating can selectively induce gene expression in the targeted tumor. It provides an useful tool for cancer gene therapy because it possibly maximizes tumor cell killing and minimizes normal tissue damage.

Adenoviridae↗

[Preliminary study on CTL enhancement induced by IL-4 gene modified HL-60 cells].

OBJECTIVE: To explore the mechanism of enhancing killing activity of tumor cell-specific cytotoxic T lymphocyte (CTL) by IL-4 gene modified tumor cells (IL-4mTC). METHODS: IL-4 gene was introduced into HL-60 cells through retroviral vector PL-IL-4-SN. Wild and IL-4 mTC were used to induce CTL responses, and cell surface molecules were assayed by flow cytometry. RESULTS: The killing activity of tumor cell-specific CTL in IL-4 mTC group was increased from 11.8% to 77.2%, about sevenfold higher than that induced by wild HL-60 cells (P < 0.01). High level expression of MHC class II antigens as well as B7-1 and ICAM-1 molecules was observed in IL-4 mTC. The expression of MHC class I antigen was not affected by IL-4 gene modification. The expression of cell surface molecules induced by IL-4 mTC was completely abrogated by anti-IL-4 McAb. A significant increase of IL-2 secretions was detected during IL-4 mTC inducing CTL responses. IL-2 secretion and CTL response were inhibited by anti-IL-4 or anti-surface molecule McAbs. CONCLUSION: IL-4 gene modification might enhance the tumor cell-specific CTL killing activities by inducing cell surface molecules expression and IL-2 secretion.

Cytotoxicity, Immunologic↗

[High efficient expression of recombinant human platelet factor IV in Pichia pastoris].

OBJECTIVE: To express recombinant human platelet factor 4 (PF4) in methanol yeast. METHODS: PF4 cDNA amplified by PCR was cloned into the mating factor alpha (MFalpha) signal sequence, downstream the alcohol oxidase 1 (AOX 1) promoter of the pPIC9 vector. The reconstructed vector was subsequently integrated into the methanol yeast P. pastoris strain GS115. The highly expressing strain was selected and the protein sequences and their biological activities were assayed. RESULTS: The amino acid sequence of rhPF4 was the same as that of natural one. The rhPF4 can neutralize the anticoagulation effect of heparin in a dose-dependent manner. CONCLUSION: The amount of rhPF4 expressed in methanol yeast meets well the scale for manufacturing. The biological activities of the rhPF4 were the same as that of natural PF4.

Cloning, Molecular↗

[The association between polymorphism of endothelial nitric oxide synthase gene and diabetic nephropathy].

OBJECTIVE: To investigate the association between a 894 G-->T mutation at exon 7 and a 27 base pair(bp) repeat polymorphism in intron 4 of the eNOS gene and diabetic nephropathy in Chinese. METHODS: A case control study of 228 Chinese subjects (including 143 type 2 diabetes mellitus with or without nephropathy and 85 normal controls) was performed. The number of 894 G-->T mutation allele and 27 bp repeat polymorhism alleles were determined by polymerasechain reaction restriction fragment lenth polymorphism(PCR-RFLP) method and PCR combined with 4% agarose electrophoresis. RESULTS: The frequency of the T allele and TG genotype at exon 7 and the a allele and ab genotype in intron 4 were significantly higher in diabetic nephropathy positive (DN+) group than in diabetic nephropathy negative (DN-) group and control subjects(P < 0.05). Diabetic patients with coexistence of the T and a alleles had a higher incidence of diabetic nephropathy(P < 0.05) than those with only one of the two alleles or without any of the two alleles. Multivariate logistic regression analysis showed that blood glucose, GHbA1c, SBP, TC, 894 G-->T mutation at exon 7 and a 27 base pair(bp) repeat polymorphism in intron 4 of the eNOS gene are independent risk factors for diabetic nephropathy. CONCLUSIONS: The T allele at exon 7 and a allele in intron 4 are related to diabetic nephropathy in Chinese patients with type with 2 diabetes mellitus. The incidence of diabetic nephropathy is higher in patients who have both T and a alleles than patients who have either T or a allele alone.

Aged↗

[Cloning and nucleotide sequencing of full length L segment cDNA of Hantavirus strain A9].

OBJECTIVE: Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9. METHODS: The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning. RESULTS: The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment. CONCLUSIONS: The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.

Amino Acid Sequence↗

The TGF beta receptor endoglin in systemic sclerosis.

Immunohistochemical, flow cytometric and ELISA studies were performed to examine the expression of endoglin (CD105, a TGF beta receptor) on dermal endothelial cells, peripheral blood monocytes and free and bound serum levels in patients with systemic sclerosis as compared with appropriate controls. Endoglin was found to be significantly upregulated on dermal blood vessels in patients with scleroderma (and in patients with inflammatory skin disorders) as compared to healthy skin (p < 0.05). In contrast, there was no significant difference in endoglin expression on circulating blood monocytes between scleroderma patients and patients with a rheumatic disoder or healthy control subjects; however, endoglin expression was upregulated on monocytes in inflammatory joint fluid from patients with rheumatoid arthritis. Endoglin expression on monocytes was also influenced by isolation techniques and during whole blood culture. No differences were found in circulating free or bound endoglin levels between scleroderma patients and healthy controls. In conclusion, endoglin expression on dermal endothelial cells was significantly enhanced in scleroderma but levels on circulating monocytes and in the serum were within normal limits. The functional significance of this upregulation is uncertain but may reflect endothelial activation in scleroderma.

Aged↗

One hundred and seven middle-aged and senile cases of coronary heart disease with ventricular premature beat treated by qing xin an shen fang.

The therapeutic principle of clearing away the heart-heat to induce tranquilization was adopted in 107 middle-aged and senile patients with ventricular premature beat of coronary heart disease on the basis of pathogenic features of phlegm, heat, blood stasis and deficiency in this condition. Qing Xin An Shen Fang ([symbol: see text] a formula for clearing away the heart-heat to induce tranquilization) was used in the treatment group and compared with mexiletine and Fu Fang Dan Shen Tablets ([symbol: see text] Compound Salvia Tablets) used in the control group. The results turned to be that the markedly effective rate was 85.1% and the total effective rate 96.3% in the treated group, better than that in the control group, with the former having a good antihypertensive and antihyperlipemic effect and an effect of improving microcirculation and clinical symptoms.

Aged↗

Effect of acupuncture on plasmic levels of insulin, glucagon and hypercoagulability in NIDDM complicated by acute cerebral infarction.

Twenty-one cases of acute cerebral infarction secondary to NIDDM were treated with acupuncture and conventional therapy, and compared with 16 cases treated with conventional therapy alone. The results showed that acupuncture was more effective in reducing insulin and glucagon levels (P < 0.001) and improving hypercoagulability (P < 0.05) of blood.

Acupuncture Therapy↗

Effect of buyang huanwu decoction on platelet activating factor content in arterial blood pre- and post-arterial thrombosis in rats.

To explore the effect of Buyang Huanwu Decoction (BHD) on platelet activating factor (PAF) content in arterial blood pre- and post-arterial thrombosis in rats, male Wistar rats were randomly divided into 3 groups, the medicine group treated with BHD, the control group with dexamethasone liquid, and the blank group with distilled water. Oral administration was given for 14 consecutive days, once daily. Model of arterial thrombosis was established in the animals 2 hours after final medication, the blood content of PAF, dry weight (DW) and occlusion time (OT) of thrombus, and dry weight of thrombus/body weight (TW/BW) ratio were observed. Results indicated that BHD could markedly lower the arterial blood content of PAF after thrombosis, increase the OT of thrombus, reduce the dry weight of thrombus and the TW/BW ratio (P < 0.05). It is suggested that BHD can inhibit the pathologic PAF metabolism and formation and development of arterial thrombus.

Animals↗

[Preparation of cucurbitacinBE polylactic acid nano-particles for targeting cervical lymph nodes].

OBJECTIVE: Anti-cancer nano-particles for targeting cervical lymph nodes were designed and prepared on the basis of the physiologic and anatomic properties of the peri-oral cancer lymphatic capillaries. METHODS: The biodegradable polylactic acid (PLA) was selected as the carrier material, and cucurbitacinBE (CuBE) with very high anticancer activity against oral squamous cell carcinoma was used as the model drug. According to the criteria of the diameter of the nano-particles, drug loading (DL) and embedding ratio (ER), the preparing technology was optimized by uniformly designing experiment on the basis of single-factor experiment. CucurbitacinBE poly-lactic acid nano-particles (CuBE-PLA-NP) was prepared with the method of emulsion solvent evaporation, and then CuBE-PLA-NP lyophilization injection was prepared by using 10% manninositose as the supporting agent. RESULTS: The diameter distribution for optimized CuBE-PLA-NP lyophilization injection ranged from 47 nm to 120 nm, and the average diameter was 85 nm. DL and ER were 23.03% +/- 0.47% and 93.00% +/- 0.10% respectively. The release study of the thermostatics also demonstrated that Higuchi equation was adequate to fit the release curve of CuBE-PLA-NP. CONCLUSION: CuBE-PLA-NP can be used as the release agent, as CuBE-PLA-NP can enter peri-oral cancer lymphatic capillaries for targeting cervical lymph nodes by the peri-cancer submucosal injection. Therefore, it can also used for animal and clinical experiments.

Antineoplastic Agents↗

[Relationship between Streptococcus mutans, Lactobacillus spp. and lactate-producing level and nursing bottle caries].

OBJECTIVE: The study aimed to investigate the levels of Streptococcus mutans and Lactobacillus spp. as well as the relationship between lactate-productive and aciduric organisms and nursing bottle caries. METHODS: Totally, 30 children of 2- to 2.5-year-old were divided into two groups, including the group of nursing bottle caries and the group of caries-free. Streptococcus mutans and Lactobacillus spp. were isolated from dental plaque of all the children. The amount of lactate produced was measured with a microlitre plate reader. RESULTS: The isolation frequency of Streptococcus mutans and Lactobacillus spp. were both 100 percent in the children with nursing bottle caries, and that the composition of these bacteria from nursing bottle caries lesions was higher than that of caries-free dental surface. Lactate-producing level was higher in the caries group than that of the caries-free group. CONCLUSION: This study suggests Streptococcus mutans and Lactobacillus spp. may be the major pathogenic bacteria leading to nursing bottle caries.

Bottle Feeding↗