Biomedical subjects

Qiang Li

Publications and source records attributed to Qiang Li.

At least 253 records · Page 14Linked to original sources

PubMed2002

Differential effect of ethanol on NMDA EPSCs in pyramidal cells in the posterior cingulate cortex of juvenile and adult rats.

Ethanol (EtOH) is a potent inhibitor of N-methyl-D-aspartate (NMDA) receptor-mediated activity in a number of brain areas, and recent studies have indicated that this inhibitory effect of ethanol is more powerful in the juvenile brain compared with the adult brain. However, previous direct developmental comparisons have been limited to studies of extracellular responses in the hippocampus. To begin an assessment of the mechanisms underlying this developmental sensitivity, we assessed the inhibitory effect of EtOH on NMDA receptor-mediated synaptic transmission in neocortical slices from adult (95-135 days old) and juvenile (28-32 days old) rats using the whole cell patch-clamp recording technique. In the presence of 6,7-dinitroquinoxaline-2,3-dione (20 microM) and bicuculline methiodine (20 microM), NMDA receptor-mediated excitatory postsynaptic currents were isolated from pyramidal cells of the posterior cingulate cortex (PCC). In slices from juvenile rats 5, 10, 30, and 60 mM EtOH reduced the mean amplitude of NMDA receptor-mediated EPSCs by 11, 22, 35, and 46%, respectively. However, the same concentrations of EtOH inhibited the mean amplitude of EPSCs by only 4, 8, 15, and 31% in slices from adult rats. This developmental difference in the potency of EtOH against NMDA receptor-mediated EPSCs was also observed when the holding potential of the neurons was increased to +30 mV, although the inhibitory effect of ethanol on adult neurons was diminished at that voltage. These results provide a cellular analysis of the enhanced potency of ethanol against NMDA receptor-mediated EPSCs in neocortical cells from juvenile animals compared with adults.

2-Amino-5-phosphonovalerate↗

PubMed2002

Generalized beam-propagation factor of partially coherent beams propagating through hard-edged apertures.

The second-order intensity moments and beam-propagation factor (M2 factor) of partially coherent beams have been generalized to include the case of hard-edged diffraction. A laser beam with amplitude modulation and phase fluctuation and a Gaussian Schell-model beam are taken as two typical examples of partially coherent beams. Analytical expressions for the generalized M2 factor are derived.

Journal Article↗

PubMed2002

[Development of an image processing scheme for chest radiographs using a dot printer].

The performance of dot printers has recently been improved. Images output by dot printers can provide simple, economical medical reference images if important diagnostic information is not lost. We developed an image processing scheme for chest radiographs that employed a dot printer. We used two types of pixel value conversions, a nonlinear pixel value correction using a lookup table and a linear pixel value conversion using histogram analysis. The density distribution of chest radiographs was analyzed and classified into high-density and low-density images. The two types of pixel value conversions were used depending on the density of chest radiographs. Converted pixel value had density characteristics that were adapted to the output image of the dot printer, and thus the density distributions of the lungs of radiographs became comparable. In addition, an adaptive unsharp masking technique with processing parameters optimized for each of the lungs and mediastinum was applied. An ROC study for the detection of lung nodules was carried out to evaluate the performance of dot printer images. The area under the ROC curve (A(z)) for dot printer images was 0.816, while sensitivity and specificity were 77.6% and 75.2%, respectively. The performance indicated the usefulness of our image processing scheme.

Humans↗

PubMed2002

[Transferring of the pedicled second metatarsal base for repairing bone defect of lateral malleolus].

OBJECTIVE: To study the method and effect of transferring the pedicled second metatarsal base for repairing bone defect of lateral malleolus. METHODS: Thirty lower limb specimens were anatomized to observe the morphology, structure and blood supply of the second metatarsal bone. Then transferring of the pedicled second metatarsal base was designed and used in 6 patients clinically. All cases were male, aged from 24 to 48 years old, and the area of bone defect was 3-4 cm. RESULTS: Followed up for 3-11 months, all patients healed primarily both in donor and recipient sites. There were excellent results in 4 cases and good results in 2 cases. The morphology and function of the malleoli were satisfactory. CONCLUSION: Transferring of the pedicled second metatarsal base for repairing bone defect of lateral malleolus is an effective and reliable operative method.

Adult↗

PubMed2002

[Primary lymphoma of the spleen: clinical analysis of 23 cases].

OBJECTIVE: To investigate the best diagnostic and therapeutic method for primary lymphoma of the spleen. METHODS: Clinicopathologic features of 23 patients treated from January 1956 to August 1999 were analyzed retrospectively. RESULTS: All patients but one for exploration only (96%) underwent resection of the tumor. They accepted chemotherapy after operation. 23 patients were confirmed pathologically. B-cell type non-Hodgkin's lymphoma was noted in 21 patients and T-cell letion in 2. According to Ahman's staging, 9 patients belonged to stage I, 8 stage II, and 6 stage III. The 5-year survival rates were 50%, 40% and 16% respectively. CONCLUSIONS: The diagnosis of splenic lymphoma is dependent mainly on B-ultrasound examination and CT scanning. Splenectomy combined with chemotherapy may provide optimum therapy for patients with splenic lymphoma.

Adult↗

PubMed2002

[Diagnosis and treatment of congenital recessive cleft palate].

OBJECTIVE: To explore an effective method to diagnose and treat the congenital recessive cleft palate. METHODS: For the treatment of congenital recessive cleft palate, an operation was designed to recover the anatomic length and function mobility of the soft palate. The operation procedure includes incising vertically the midline mucous membrane of the soft palate, creating and pushing back the mucosal flap of the hard palate, making Z-plasty on the nasal mucosa, reconstructing the sling of the levator veli palatini muscle and repairing the palatal defects with the buccinator muscularis mucosae flap. 12 cases of congenital recessive cleft palate have treated with this method. RESULTS: All of the 12 cases obtained good results. Their pronunciation improved obviously. CONCLUSION: The method is effective for diagnosis and treatment of congenital recessive palate, which is worthy of further application.

Adolescent↗

PubMed2002

[Relationship between the Nco I, Ava II polymorphism of low density lipoprotein receptor gene and atherosclerotic cerebral infarction].

OBJECTIVE To investigate the relationship between the Nco I, Ava II polymorphism of low density lipoprotein receptor (LDL-R) gene in patients with the occurrence of atherosclerotic cerebral infarction (ACI) among the Han nationality in Liaoning province. METHODS The polymerase chain reaction technique was used to study the polymorphisms of LDL-R gene and allele frequencies in 77 patients with ACI and in 113 age-matched Chinese healthy controls. The levels of the lipid and lipoproteins were also compared among the cases with ACI and the controls. RESULTS A(+) frequencies of LDL-R gene in healthy controls and ACI group were 0.230 and 0.125 respectively, while the N(+) frequencies of healthy control and ACI group was 0.667 and 0.662 respectively. In case of the coexistence of A(-) A(-) and N(+) N(+), the relative risk (RR) of ACI was 5.56(P<0.001), while the RR of the increase of serum levels TG, TC, LDL-C, LP(a) were 4.29, 7.67, 9.33 and 3.09(P<0.05), respectively. CONCLUSION The coexistence of A(-) A(-) and N(+) N(+) can affect the concentration of lipid and lipoprotein and is in close relationship with the occurrence of ACI.

Apolipoprotein A-I↗

PubMed2002

A clinical and experimental study on the protective effects of jiangzhi tongmai fang on endothelial injury.

31 cases of atherosclerosis (AS) were treated with Jiang Zhi Tong Mai Fang ([symbol: see text], formula of JZTMF), and its effect was compared with 30 cases treated with lovastatin in the control group. Clinically, the JZTMF formula showed an effect of regulating blood lipids, and therefore it was antiatherosclerotic. The mechanism is, probably, restoration of the function of endothelial cells (EC) by increasing the synthesis of 6-keto-PGF1 alpha and decreasing the release of endothelin (ET) as evidenced in the experimental study.

6-Ketoprostaglandin F1 alpha↗

PubMed2002

Diagnosis and treatment of primary gastric non-Hodgkin's lymphoma: analysis of 157 patients.

OBJECTIVE: To seek the optimum treatment for patients with primary gastric non-Hodgkin's lymphoma and factors associated with prognosis. METHODS: A retrospective study was conducted on 157 primary gastric non-Hodgkin's lymphoma patients who had received operation for 45 years. RESULTS: The X-ray diagnosis rate was 39.4% before operation. The diagnosis rate by gastroscopy was 52.7%. Among the 157 patients, 32 belonged to stage I(E), 40 stage II(E), 29 stage III(E), and 56 stage IV(E). All of the patients were received chemotherapy or radiation. The 3-, 5-, 10-, 15-year survival rates were 51.1% (69/135), 42.3% (55/130), 20.7% (23/111), and 13.5% (14/104). CONCLUSIONS: The 3-, 5-year survival rates in stage I(E) and stage II(E) were 2 to 5 times higher than those in stage III(E) and IV(E) (P < 0.01). The 3-, 5-year survival rates of primary gastric non-Hodgkin's lymphoma were 60.2% (65/108) and 50.0% (52/104) respectively. The prognosis was better than the 5-year survival rate of gastric cancer patients with D(2) lymphodenectomy (33.3%). Early diagnosis and treatment are effective to prevent complications, enhance quality of patient's life, and prolong the survival.

Humans↗

PubMed2002

[Results of bronchoplasty by fiberoptic bronchoscopic balloon dilatation in the management of proximal benign tracheobronchial stenosis].

OBJECTIVE: To assess the effect and safety of balloon dilatation through fiberoptic bronchoscopy in the management of benign tracheobronchial stenosis. METHODS: Thirty-seven patients with proximal benign tracheobronchial stenosis were treated by balloon dilatation through flexible fiberoptic bronchoscopy. A fiberoptic bronchoscope was inserted, a balloon catheter was sent to the stenotic segment from the working channel and positioned in the stenotic bronchus. Under direct visualization, the balloon was inflated for 1 min to 3 min. Repeat inflation-deflation cycles were done if airway narrowing remained after the initial operation. Before the procedure and immediately after the last operation, airway diameters, dyspnea index and complications were evaluated in all of the patients and FEV(1) was tested in 26 of the 37 patients. RESULTS: One to 6 operations (2.4 +/- 1.1, approximately x +/- s) were required to achieve satisfactory dilatation. After high-pressure balloon dilatation, the average airway diameter increased from (2.6 +/- 1.2) mm to (6.9 +/- 1.8) mm (P < 0.01). Dyspnea index decreased from 2.0 +/- 0.8 to 0.7 +/- 0.6 (P < 0.01). FEV(1) was increased from (1.3 +/- 0.6) L to (1.8 +/- 1.0) L (P < 0.01). No severe complications were found in these patients CONCLUSION: Bronchoplasty by high-pressure balloon dilatation through flexible fiberoptic bronchoscopy is a simple but effective and safe method to treat proximal benign tracheobronchial stenosis.

Adolescent↗

PubMed2002

[Antibacterial effect of niaoluqing oral liquid on clinical drug-resistant strains and different serotype strains of Ureaplasma urealyticum in vitro].

OBJECTIVES: To study the antibacterial effect of Niaoluqing Oral Liquid (NOL) on clinical drug-resistant strains and 14 serotype strains Ureaplasma Urealyticum (UU). METHODS: Sixty-three clinical strains of UU were detected to determine their serology and antibiotic susceptibilities by the metabolic inhibition test (MIT). Mininum inhibitory concentration (MIC) was used to evaluate the sensitivity of NOL to different serotypes of UU. The sensitivity of NOL, erythromycin and tetracycline to 63 clinical strains of UU was also studied. RESULTS: In 63 clinical strains of UU, the range of MIC to NOL was from 0.48 mg/ml to 15.63 mg/ml, MIC50 < or = 1.95 mg/ml, MIC90 < or = 3.91 mg/ml. Among them, 31 strains were resistant to tetracycline and 31 were resistant to erythromycin. No obvious correlation between the sensitivity of NOL to UU clinical strains and that of erythromycin and tetracycline to UU clinical strains (P > 0.05). Clinical strains of UU in this experiment contains all of its serotypes, also having a higher sensitivity to NOL (MIC < or = 3.91 mg/ml) except serology 1, 2, 3 and 11 (MIC > or = 7.81 mg/ml). CONCLUSIONS: NOL exerts a strong in vitro antibacterial effect on erythromycin-resistant and tetracycline-resistant clinical strains of UU. All kinds of serotype strains had a higher sensitivity to NOL, too. Chinese medicinal herbs are of momentous significance in the treatment of UU infection.

Anti-Bacterial Agents↗

PubMed2002

[Clinical and pathological investigation of polymyositis and dermatomyositis: report of 83 cases].

OBJECTIVE: To study the clinical and pathological characteristics and treatment of polymyositis (PM) and dermatomyositis (DM). METHODS: Eighty-three DM/PM cases were reviewed and analyzed. RESULTS: The main clinical presentations of PM/DM included amyosthenia, muscular tenderness, elevation of serum enzymes, accompanied by abnormal electromyography and muscular pathology. A total efficacy rate of 86.7% was achieved after treatment with corticosteroid and immuno- depressants. CONCLUSION: The different clinical and pathological presentations of various types of PM/DM suggest different pathogenesis between DM and PM. Nerve damage is a part of the systemic damages due to the disease, the prognosis of which is related to its classification and then timing of the treatment. Early effective treatment can improve the prognosis.

Adolescent↗

PubMed2002

[Microvascular structure of the transmidline scapular flap].

OBJECTIVE: To investigate the microvascular structure of the transmidline scapular flap pedicled with the unilateral circumflex scapular artery. METHODS: Latex and ink mixture was injected into the unilateral circumflex scapular artery of 6 fresh cadavers. The transmidline scapular flap was dissected and the pellucid specimen was made. The artery perforators were traced to their underlying parent vessels that accompanied the segmental arteries. A series of cross-sectional studies were undertaken in one subject to illustrate the course of the perforators in the tissues of different depth. RESULTS: In deep and superficial fascia, the subdermal and dermis layer, rich microvascular connection was found which showed in three patterns: the vascular arch, communicating branches, and the arterial rate. They interrelated to form a three-dimensional framework. The vascular tree not only passed the midline but also reached the contralateral acromion. The densest vessels were exhibited at the injection side of the back. In the midline area the vessels were in less density and at the contralateral side, the vessels mainly concentrated in the upper part of the back. CONCLUSION: The result evidenced the vascular pattern and the applicable safety of the transmidline scapular flap. In elevating a transmidline scapular flap, the distal part should mainly locate at the upper part of the back.

Adult↗

PubMed2002

[Treatment of chordee without hypospadias].

OBJECTIVE: To investigate the methods of dealing with chordee without hypospadias. METHODS: From November 1982 to December 2000, 18 cases of chordee without hypospadias were treated using the methods of urethra extension, urethra elongation with a pedicled transverse prepuce entoplastron flap, a longitudinal prepuce flap or a scrotum mediastinum flap. RESULTS: One case was cured with the first method; 5 cases with the second method; 6 cases with the third method; 6 cases with the fourth method. Fistula occurred in one case treated with the second method. CONCLUSION: The essential defect of chordee without hypospandias is short of urethral tissue. The principal treatment is repairing the urethra using tissue transplatation. Different method should be used based on the characteristics of the defects.

Adolescent↗

PubMed2002

[Synergistic effect of toremifene and cisplatin on human lung cancer cell line A549].

OBJECTIVE: To study the toxic effect of toremifene (TOR) and its synergistic effect with cisplatin (DDP) on human lung adenocarcinoma cell line A549. METHODS: The cytotoxic effects of these agents on human lung cancer cell line A549 were monitored by a tetrazolium-based colorimetric assay (MTT assay). The cell cycle and DNA content were detected by flow cytometer technic. p21 expression level was monitored by Western blot. RESULTS: Toremifene inhibited the growth of A549 cell, with > or = 5 micromol/L significantly enhancing the chemosensitivity of cisplatin. TOR enhanced the antitumor activity of DDP at S, G(2) and M phases of cells. And p21 expression was increased after TOR and DDP had been given. CONCLUSION: Toremifene (> or = 5 micromol/L) combined with cisplatin shows significant synergistic anti-tumor effect on A549 cells.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Study on the relationship between mitochondrial gene mutation and latent autoimmune diabetes mellitus in adults.

OBJECTIVE: To identify the A3243G mutation of mitochondrial (mt) DNA in patients with latent autoimmune diabetes mellitus in adults (LADA) of Han nationality in the northeast area of China. METHODS: Seventy-nine diabetics of Han nationality, whose families have resided in the northeast area of China for more than 3 generations, were divided into 3 groups: Group 1 (22 cases of type 2 diabetes with maternal inheritance history), Group 2 (34 cases of LADA), Group 3 (23 cases of type 1 diabetes in adolescents). The A3243G of mt DNA was detected in these 79 subjects with the method of PCR-RFLP. RESULTS: None of the 79 diabetics studied was positively identified for the A3243G mutation of mt DNA. CONCLUSION: The A3243G mutation of mt DNA might not be related to the onset of LADA in diabetic population of Han nationality in northeast area of China and there might not be close relationship between A3243G mutation of mt DNA and autoimmunity.

Adolescent↗

PubMed2002

[Determination of trace copper based on the fluorescence quenching of phenanthroline].

A fluorescence quenching method for the determination of trace Cu (II) was developed. The method was based on the fluorescence quenching effect of phenanthroline due to the formation of a non-fluorescent complex in pH 6.25-7.55 KH2PO4-Na2HPO4 medium. The excitation and emission wavelengths are 266 and 368 nm, respectively. The linear range is 8-300 ng.mL-1 and the detection limit is 10.4 ng.mL-1. The method has been satisfactorily used to determine trace amounts of Cu (II) in standard environmental water samples with sulfhydryl cotton separation.

Copper↗

PubMed1999

Mutagenesis of hupT Gene and H(2)-uptake Hydrogenase Expression in Photosynthetic Bacterium SDH2.

HupT(-) insertion mutants, SDHT1 and SDHT2, were constructed by the homologous double exchange between the host, Rodobacter sp. SDH20, and the hupT gene fragment with a kan(R) gene inserted on pSE8, a suicide plasmid, which had been introduced into the host by using triparental conjugation. The HupT(-) mutants were verified by Southern hybridization. H(2)-uptake hydrogenase activity analysis revealed that the H(2)-uptake hydrogenase activities of HupT(-)mutants were two-fold as that of wild type strain SDH20 when grown anaerobically in MN medium and aerobically in MG or MN medium, and had no distinct improvement relative to wild type strain when grown anaerobically in MG medium. The expression analysis of hupS confirmed that the HupT- mutants exhibited two- to three-fold increase of the expression of hupS relative to wild type strain when grown anaerobically in MN medium and aerobically in MG or MN medium, but no obvious increase when grown anaerobically in MG medium. These results demonstrate that hupT regulates negatively the synthesis of H(2)-up-take hydrogenase in the photosynthetic bacterium strain SDH2.

Journal Article↗