Biomedical subjects

F Li

Publications and source records attributed to F Li.

At least 91 records · Page 5Linked to original sources

PubMed2001

Percutaneous balloon angioplasty of coarctation of the aorta in children: 12-year follow-up results.

OBJECTIVE: To evaluate the efficiency of percutaneous balloon angioplasty of coarctation of the aorta in children and discuss its risk factors that can lead to poor long-term results. METHODS: From September 1987 to August 1999, 24 patients underwent 27 balloon angioplasty procedures for native or recurrent coarctation of the aorta at our institution. There were 19 patients with discrete (membranous) coarctation, 4 patients with long-segment and aortic arch hypoplasia, and 1 patient with postoperative recurrence. The balloon diameter was chosen not to exceed the diameter of the aorta proximal to the stenotic site (11.06 +/- 2.80 mm vs 11.78 +/- 3.18 mm), with the chosen diameter two to four times that of the stenotic segment (2.57 +/- 0.68 times). The patients have been followed up for half to twelve years (mean 6.2 +/- 2.8 years). Satisfactory result was defined as a reduction in the pressure gradient across the site of coarctation to < or = 20 mm Hg. RESULTS: The systolic pressure gradient across the coarctation site decreased from 48.17 +/- 14.68 mm Hg to 14.96 +/- 13.12 mm Hg (P < 0.01) and the diameter of the coarctation site increased from 4.66 +/- 2.43 mm to 8.80 +/- 3.32 mm (P < 0.01). Immediate satisfactory results were obtained in 19 patients (79%). Of the 5 patients with unsatisfactory results, 4 had aortic arch hypoplasia and 1 had membranous coarctation. Of the 19 patients with satisfactory results, 18 patients had membranous coarctation and 1 patient had recurrent postoperative coarctation. No aneurysm and other complications had occurred in any patients at the follow-ups. CONCLUSION: Percutaneous balloon angioplasty is an effective treatment alternative to surgery in most patients with recurrent postoperative or native membranous coarctation of the aorta. It should not be recommended for the coarctation of aortic arch hypoplasia.

Adolescent↗

PubMed2001

All-trans retinoic acid in pulmonary vascular structural remodeling in rats with pulmonary hypertension induced by monocrotaline.

OBJECTIVE: To determine whether all-trans retinoic acid (atRA) exerts an inhibitory effect on rats with pulmonary hypertension induced by monocrotaline. METHODS: All rats were given a single subcutaneous injection of either monocrotaline (60 mg/kg) or saline. Monocrotaline-injected rats received either atRA (30 mg.kg-1.day-1) or saline through oral-gastro intubation. On Days 7, 14, 21, and 28 respectively after monocrotaline injection, cardiovascular catheters were inserted to examine the mean pulmonary artery pressure of rats in each group. Meanwhile, the matrix metalloproteinase-1 (MMP-1) mRNA expression and hydroxyproline content in the main pulmonary artery were determined by RT-PCR and chromometry, respectively. RESULTS: The mean pulmonary artery pressure of rats in the model group increased significantly on day 21 and reached a peak on Day 28 compared with the control group (25.7 +/- 4.3 mm Hg vs 15.1 +/- 1.5 mm Hg and 38.5 +/- 6.4 mm Hg vs 16.4 +/- 2.0 mm Hg, P < 0.01). MMP-1 mRNA overexpression was present on Day 14 (0.72 +/- 0.15 vs 0.39 +/- 0.08, P < 0.01) and was rapidly down-regulated on Day 21 and 28 compared with Day 14, but was still higher than that in the control. The hydroxyoroline content of the main pulmonary artery dropped significantly on Day 14 (4.01 +/- 1.13 micrograms/mg vs 5.10 +/- 0.91 micrograms/mg, P < 0.05) and increased significantly on Days 21 and 28 compared with the control. atRA inhibited the MMP-1 mRNA overexpression from Day 14 to Day 28 and reduced the hydroxyproline content (5.59 +/- 0.70 micrograms/mg vs 7.96 +/- 1.13 micrograms/mg and 7.77 +/- 0.96 micrograms/mg vs 9.93 +/- 1.27 micrograms/mg, P < 0.01) and the mean pulmonary artery pressure compared with the model group (19.6 +/- 3.2 mm Hg vs 25.7 +/- 4.3 mm Hg and 26.3 +/- 4.6 mm Hg vs 38.5 +/- 6.4 mm Hg, P < 0.01). CONCLUSION: atRA inhibits MMP-1 overexpression and the accumulation of collagen, which might elicit favorable geometric remodeling in rat pulmonary hypertension induced by monocrotaline.

Animals↗

PubMed2001

Nested polymerase chain reaction in detection of Plasmodium vivax sporozoites in mosquitoes.

OBJECTIVE: To detect malaria DNA in mosquitoes. METHODS: A nested polymerase chain reaction (nested PCR) procedure which amplifies a 121 bp DNA of a SSUrRNA gene specific to Plasmodium vivax was used. RESULTS: In laboratory-infected mosquitoes, nested PCR could detect as few as 3 sporozoites or 1 infected mosquito mixed in a group of 99 normal ones. Furthermore, no specific 121 bp band was seen with DNA templates from other malaria parasites or negative mosquitoes. CONCLUSION: Sensitivity and specificity obtained indicated an advantage of the nested PCR over DNA probes or direct PCR for the detection of Plasmodium vivax sporozoites in mosquitoes with low-grade parasitic infections.

Animals↗

PubMed2001

[Evaluation of intraperitoneal chemotherapy in stage IV gastrointestinal cancer].

OBJECTIVE: To evaluate the short term and long term therapeutic effects of intraperitoneal versus intravenous chemotherapy in 56 cases with stage IV gastrointestinal cancer. METHODS: The patients were randomly divided into two groups: 35 cases in the intraperitoneally treated group and 21 cases in the intravenously treated group. The short term effects and side effects were observed. The survival time of the patients was also recorded. The survival function was estimated by Kaplan-Meier method, and the significance test was done by Log rank method. RESULTS: There was no significant difference between the two groups in short term effects, and liver and kidney damages. Nausea, vomiting and bone marrow suppression were more severe in the intravenously treated group, while abdominal distension and pain were the major side effects in the intraperitoneally treated group. The median survival time and one year survival rate of patients in the intraperitoneally treated group were higher than those in the intravenously treated group. CONCLUSION: For patients with stage IV gastrointestinal cancer, intraperitoneal administration of chemotherapeutic agents is a better treatment of choice.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

[Estimation of insulin secretion rate in multiple sampled intravenous glucose tolerance test].

OBJECTIVE: To measure and calculate insulin secretion rate(ISR) in multiple sampled intravenous glucose tolerance test (FSIVGTT) according to the two compartment model and standard parameters of the kinetics of connecting peptide (C-P) in vivo. METHODS: 15 subjects with normal glucose tolerance and 11 type 2 diabetic patients took part in the study. Oral glucose tolerance test (OGTT) and FSIVGTT were performed. Glucose concentrations were measured by hexokinase method. Insulin (INS) and C-P concentrations were measured by radioimmunoassay. A computer procedure devised by our laboratory was used to calculate the value of ISR at each time point. RESULTS: In the control group, serum INS and C-P concentrations reached the peak at 4 min, the second peak was not obvious. In type 2 diabetes, only 5 subjects had a small peak within 4 min, two curves reached its peak between 60 and 80 min. In the control group, ISR reached its peak 2 min after injection of glucose, that was earlier than INS and C-P curves in time sequence (P = 0.000), the second obvious peak was shown at 22 min. In type 2 diabetes, an obvious but small peak of ISR was shown at 2 min and all the patients had this peak. CONCLUSIONS: It is necessary to take the process of metabolic clearance of INS and C-P into consideration, when blood concentration of INS and C-P were used as indexes to evaluate the secretion function of beta-cells. The ISR profile is more sensitive for investigation of the second phase of insulin secretion in the control group and the first phase in type 2 diabetes group.

Blood Glucose↗

PubMed2001

[Studies on the manufacture and immunogenicity of purified rabies vaccines on humans Vero cell].

OBJECTIVE: Using Vero cell as basic cultural material to improve the quality of rabies vaccines and to produce rabies vaccines for humans. METHODS: CTN-1V10 strain were used for production. Vero cell of 150th generation were used for cultivation. Rotating cultivatal method with rotating bottle was used. Fluids with virus were collected at different time. Puritied rabies vaccine was produced on Vero cell after clarification, condensation, purification and extermination. A batch of vaccines made by this techniques were used for immunological observation. Sixty-three people were injected with this rabies vaccine according to the procedure of time of exposure. Thirty of them were injected with vaccines made in France (Verorab) while the others were injected with vaccines to be tested. Side effect and neutralizing antibody were recorded. RESULTS: The quality of this newly developed rabies vaccines has met the quality set by WHO. After all dosages of injection, the rates of positive antibody were both 100% in two groups. The neutralizing antibody among testing group was 11.94 IU/ml comparing with control as 11.69 IU/ml. CONCLUSION: Purified rabies vaccines on Vero cell for humans had reasonable manufacture technique and less little effect with good technological imnunogenicity.

Animals↗

PubMed2001

[An epidemiological survey of blindness and low vision in Meixian County].

OBJECTIVE: To study the status of blindness and low vision in Meixian County. METHODS: The stratified random sampling rule and the standard grading system of blindness set by WHO were adopted in the study, and 11 327 subjects were enrolled (a sampling fraction of 2.01%) in the whole county. RESULTS: The prevalence of bilateral blindness and low vision was found to be 0.47% and 0.89%; that of monocular blindness and low vision was 0.72% and 0.59%, respectively. Subjects over 50 years old had a significantly higher prevalence of blindness and low vision. The causes leading to blindness and low vision were, in falling order, cataract, glaucoma, ametropia/amblyopia and pterygium. CONCLUSION: The treatment of cataract is the main measure to decrease the prevalence of blindness and low vision.

Adolescent↗

PubMed2001

[Revision of thin-walled cystic bleb by transposing conjunctival flap technique].

OBJECTIVE: To investigate the clinical effect of transposing conjunctival flap technique on thin-walled cystic blebs after trabeculectomy for treatment of glaucoma. METHODS: Fifty-two eyes of 46 patients with thin-walled cytic blebs were underwent this modified operation. The procedure involved incising the conjunctiva surrounding the preserved bleb, then the conjunctiva-Tenon's fascia flap superior or temporal to the cystic bleb was relaxed and mobilized to cover the bleb surface after topical cryopexy. The anterior margin of the flap was sutured onto the peripheral cornea. In order to relax the conjunctival flap sufficiently, an incision was made close to the superior fornix above the flap and parallel to limbus to decrease the tension. RESULTS: In the follow-up of 6 months-4 years, the mean intraocular pressure (IOP) of 52 eyes increased to postoperative (12.98 plus minus 5.70) mm Hg from preoperative (4.25 plus minus 1.33) mm Hg (1 mm Hg = 0.133 kPa) (t = 3.26, P < 0.01), 51 eyes maintained the filtering function. Post-operatively, the bleb leakage in 20 eyes and macular edema in 6 eyes disappeared. Local antiglaucoma medication was required in one eye, because the bleb disappeared with increasing IOP. The post-operative visual acuities were elevated in comparison with that before the operation (chi(2) = 16.65, P < 0.01). CONCLUSION: The transposing conjunctival flap technique is an effective surgery for the repair of thin-walled cystic bleb whose complications, such as hypotony, maculopathy, bleb leakage or endophthalmitis can be cured or prevented.

Adolescent↗

PubMed2001

[The relationship of clinicopathology and immunophenotypes in non-Hodgkin's lymphomas of the spleen].

OBJECTIVE: To investigate the relationship between clinicopathologic features and immunophenotypes in non-Hodgkin's lymphoma (NHL) of the spleen. METHODS: Clinicopathologic analysis and follow up; immunohistologic staining by SP method and EBER in situ hybridization. RESULTS: (1) Splenomegaly was found in all 19 cases of spleen NHL, 10 of the 19 (52.6%) cases had masses or a mass in their enlarged spleen; (2) 14 of the 19 (73.7%) cases were of B-cell type (including 5 cases of follicular type and 9 cases of diffuse type), in which 8 cases were centroblastic, 3 of centroblast/centrocyte and 4 cases of small lymphocyte types; all 10 cases of primary splenic lymphomas (PSL) were B-cell type; (3) 5 of the 19 cases (26.3%) had peripheral T-cell origin, including 4 cases of large cell type and 1 case of small cell type; of the 3 TIA-1 positive cases, 2 were also positive for EBER 1/2 (one CD 8+ and another CD56+), the remaining case was CD8-, CD56-, EBER1/2-; all 5 cases were secondary NHL of the spleen; (4) Follow up data were obtained for 14/19 cases (73.7%). 8 of 9 surviving cases were primary NHL. The range of survival period varied from 8 to 10 years. All 5 deceased cases had secondary NHL and their survival period was 2 to 6 months. CONCLUSIONS: Some relationship exists between the clinicopathology and origin of the tumor cells in splenic NHL, the prognosis of primary NHL is better than that of the secondary NHL and the diagnosis of primary NHL should be made with discretion.

Adolescent↗

PubMed2001

[Cytotoxic natural killer/T-cell lymphomas of the lymph nodes].

OBJECTIVE: To investigate the clinicopathologic features of cytotoxic natural killer (NK)/T-cell lymphomas of the lymph nodes. METHODS: Clinicopathologic observations and follow up on 5 cases of cytotoxic NK/T-cell lymphomas of the lymph nodes, immunohistochemical staining for CD45RO, CD8, CD56, CD30, CD20, TIA-1 and in situ hybridization for EBER1/2 were performed. RESULTS: (1) The clinicopathologic features of cytotoxic NK-T-cell lymphomas of the lymph nodes were summarized; (2) The tumor cells were positive for CD45RO in 4 of the 5 cases, in which 3 cases were also positive for CD56. One case was of null cell type. The tumor cells were positive for TIA-1 and EBER1/2 in all 5 cases. CONCLUSIONS: The clinicopathological features and special immunophenotypes of cytotoxic NK/T-cell lymphomas of the lymph nodes were present in all 5 cases. Clinically, this entity tends to be an aggressive process with poor prognosis.

Adult↗

PubMed2001

[Antimetastatic effects of arginine-aspartate on salivary adenoid cystic carcinoma in vitro].

OBJECTIVE: To test the effects of arginine-aspartate (RD) on metastasis of salivary cystic carcinoma (SACC). METHODS: Highly metastatic SACC cell line SACC-LM was used in the study. The effect of RD on tumor cell-ECM adhesion was assayed by MTT technique. The effect of RD on invasion and migration of SACC-LM were evaluated using modified boyden chamber. RESULTS: RD inhibited tumor cell fibronectin adhesion at 5 mg/L concentration, but no effects on tumor cell laminin and tumor cell type IV collagen adhesion. RD inhibited the invasion at 1, 5, 25 mg/L, and inhibited the migration only at 25 mg/L. CONCLUSIONS: The result shows that the RD has an antimetastatic effect on SACC-LM cells in vitro.

Antineoplastic Agents↗

PubMed2001

[Expression of Fas and Fas ligand in lesions of patients with discoid lupus erythematosus].

OBJECTIVE: To study the relation of apoptosis and pathogenesis of lupus erythematosus. METHODS: Expressions of Fas and Fas ligand(FasL) were detected in 30 lesions of discoid lupus erythematosus(DLE) and 5 skin specimens from healthy controls by immunohistochemical staining. RESULTS: Fas and FasL were positively expressed in most epidermal keratinocytes, infiltrating lymphocytes around blood vessels and appendages, and Fas was positively expressed in a few sweat ducts and hair follicles. Fas and FasL expressions were weakly positive or negative in healthy controls. CONCLUSION: Apoptosis induced by Fas, FasL pathway may be related to the pathogenesis of lupus erythematosus.

Adult↗

PubMed2001

[A study of the acting mechanism of aspirin for resistance to oxidative damage].

OBJECTIVE: To explore the mechanism of aspirin for resistance to oxidative damage in endothelial cells. METHODS: Using cultured endothelial cells, we measured the levels of aspirin induced ferritin expression on resistance to hydrogen peroxide toxicity toward cells in the presence of the iron chelator desferrioxamine added to FeCl3. RESULTS: Aspirin at low concentration (0.1 mmol/L) induced significant increase of ferritin expression in a time- and concentration-dependent fashion up to 25% over basal levels(P < 0.05). Preincubating the cells for 8 h with aspirin (0.1 mmol/L) reduced lactate dehydrogenase(LDH) release rate by 50%, toxicity reduction by 40%, and significant decrease of malondialdehyde (MDA) production. Aspirin induced cytoprotection from H2O2 damage was also in a concentration- and time-dependent fashion. However, in the presence of the iron chelator desferrioxamine, aspirin enhanced ferritin synthesis was abrogated, in contrast, FeCl3 increased aspirin induced ferritin synthesis in cells. CONCLUSION: The study suggested that the antioxidation of aspirin was brought into action by affecting the cellular iron metabolism pathway to induce ferritin synthesis.

Antioxidants↗

PubMed2001

[The study on the occult metastases to cervical lymph node in squamous cell carcinoma of the larynx and hypopharynx].

OBJECTIVE: To study the metastastic regularity of cervical lymph node in squamous cell carcinoma of the larynx and hypopharynx, which will provide some theoretical basis for surgeon to use selective neck dissection (SND) in some patients with carcinoma above. METHOD: Sixty-nine originally cN0 staged neck dissection specimens from 40 patients were evaluated using mutipl-level sectioning in 4 microns intervals, which were respectively processed by H&E-staining and immunostaining with an antibody to cytokeratin (CK AE3). These patients weren't given any treatment (radiotherapy or chemotherapy or surgery in neck) before surgery. All cases had been followed up 1 year or more. RESULT: The examination of lymph nodes from 40 patients revealed 31 (0.59% 31/2219) occult metastases in 14 (35% 14/40) patients. Among them, six patients with supraglottic cancer, 1 patient with transglottic cancer and 7 patients with hypopharyngeal cancer. There were no occult metastases to cervical lymph node among 9 patients with glottic cancer. All occult metastases mainly located in ipsilateral level II and/or level III. Occult metastases weren't found in nodes from level I, level IV and level V. CONCLUSION: The study further prove that metastases to cervical lymph node mainly occur in the ipsilateral level II and level III among patients with carcinoma of the larynx and hypopharynx. According to the risks of occurring occult metastases to cervical lymph node, we suggest applying to ipsilateral or bilateral SND (level II and level III be dissected) among patients with carcinoma of the larynx and hypopharynx which staged T2-T4 N0M0 clinically.

Adult↗

PubMed2001

Simultaneous determination of sixteen phenylurea herbicides in water by high performance liquid chromatography and solid phase extraction.

A high performance liquid chromatography (HPLC) procedure for simultaneous determination of sixteen phenylurea herbicides in water is described. A Lichrospher 100 RP-18e column and spectrophotometric detection at 240 nm were used. Adequate retention was achieved with a mobile phase of acetonitrile/water solution with gradient elution. The HPLC analysis time was less than 20 min. The herbicides were isolated from water samples by using a single solid phase extraction procedure with C18 solid-phase columns. An enrichment factor of 1,000 was achieved. Recoveries were in the range between 87.8% and 103.7%. The detection limits of the whole procedure achieved were less than one-tenth of the maximum limit permitted by the European Community standard for drinking water.

Chromatography, Gas↗

PubMed2001

[Isolation, purification and identification of metallothionein from strain BD102 of Hansenula anomala].

Metallothionein (MTs) in Cu and Cd resistant strain BD102 of Hansenula anomala were induced by administration of Cu2+ and Cd2+. These proteins were isolated and purified by Sephadex G-50 and subsequent DEAE-Sepharose CL-6B, then Sephadex G-25 for desalation. There were two isoform MTs by Cu(Cu-MTs), one form induced by Cd (Cd-MT). The molecular weights of the Cu-MTs and the Cd-MT were about 7 kD and 7.5 kD respectively. Exposure of Hansenula anomala to copper salts stimulated formation of two isoform Cu-MTs with a cysteine content of 6.6-6.8% and had 60 amino acids. Exposure of Hansenula anomala to cadmium, stimulated formation of Cd-MT with a cystein content of 10% was synthesized and had 61 amino acids. 4 atom Cu or Cd/mole MTs.

Amino Acids↗

PubMed2001

[Purification and characterization of a DNA helicase from the hyperthermophilic archaeon Sulfolobus shibatae].

A DNA helicase from the hyperthermophilic archaeon Sulfolobus shibatae has been purified to homogeneity by column chromatography on Q Seqharose, phosphocellulose P11, heparin agarose, Superdex 200 and phenyl Superose. The purified enzyme shows DNA-stimulated ATPase activity. The molecular mass of the enzyme is approximately 63 kD. The S. shibatae DNA helcase is capable of unwinding a 70 bp duplex DNA flanked by unpaired single-stranded tails at both ends. The helicase activity requires Mg2+ and hydrolysis of ATP, and is inhibited by NaCl at concentrations greater than 200 mmol/L. It has an optimal pH of 6.7. The enzyme is active at temperatures between 40 and 80 degrees C, and the activity peaks at 70 degrees C. The S. shibatae DNA helicase is the first native DNA helicase to be isolated from archaea.

Adenosine Triphosphatases↗

PubMed2001

[Cloning and sequencing of 16S rRNA gene of Phytoplasma CWB1 strain associated with cactus witches' broom].

A 1.5 kb DNA fragment was amplified in DNA samples extracted from Opuntia salmiana porm showed witches'-broom symptom. The result indicates the existence of phytoplasma associated with this disease and this phytoplasma was designated as CWB1. The amplified fragment was ligated to pGEM-T easy vector and then transformed into JM109 strain of E. coli. Cloned DNA fragments were verified by PCR, restriction endonuclease (EcoRI) digestion and sequence analysis. The result revealed that the 16S rRNA gene of CWB1 consists of 1489 bp and shared 99.7% homology with Faba bean phyllody which belongs to phytoplasma 16S rII-C subgroup. So we can classify this strain into phytoplasma 16S rII-C subgroup.

Cloning, Molecular↗