Biomedical subjects

X Yang

Publications and source records attributed to X Yang.

At least 469 records · Page 26Linked to original sources

PubMed2000

[A study on apoptosis and activity of SAPK/JNK in adrenocortical cells induced by cadmium chloride].

OBJECTIVE: To study apoptosis induced by cadmium chloride and the alteration in activity of stress activated protein kinase (SAPK) in adrenocortical cells. METHODS: Fasciculata-glomerulosa (FG) cells of male guinea pigs were dispersed and primarily cultured in vitro. Features of apoptotic cells were observed using combined labeling with annexin-V and propidium iodide (PI) and flow cytometry, and activity of SAPK was determined with immunoprecipitation and chemiluminescence assay. RESULTS: Apoptosis rate of FG cells increased with dose of cadmium chloride (CdCl(2)) two hours after treatment with 6.25 - 200.00 micromol/L of it. The average percentages of apoptotic cells ranged from 9.90% to 82.35%, with significant difference in the groups treated with 25, 50, 100 and 200 micromol/L of CdCl(2), as compared with the control group (P < 0.01). Regression analysis showed that occurrence of apoptosis correlated with the dose of cadmium chloride in a dose-response pattern. In the meanwhile, there were obviously elevated percentages of apoptotic cells as the increase in duration of incubation, ranging from 5.58% to 73.08% for incubating cells with 50.00 micromol/L of CdCl(2), from 15 minutes to four hours. Duration of incubating cells with cadmium chloride correlated to occurrence of apoptosis in a time-effect manner. There were no remarkable changes in the activity of SAPK in adrenocortical cells two hours after incubation with 25.00 - 100.00 micromol/L of CdCl(2). CONCLUSIONS: Apoptosis can be induced by cadmium chloride in adrenocortical cells and its mechanism should be studied further.

Adrenal Cortex↗

PubMed2000

[Repairing severe deep burn wound with transplantation of the latissimus dorsi myocutaneous flap].

OBJECTIVE: To repair the deep wound caused by high voltage electric injury and hot mangle injury with the latissimus dorsi myocutaneous flaps. METHODS: Latissimus dorsi myocutaneous flaps were applied to repair deep burn wounds in 26 cases in which 25 were island flap transposition and 1 free flap transplantation. RESULTS: The biggest flap in this group was 40 cm x 20 cm. All flaps survived but one exception with tip necrosis of the flap. Reconstruction of the Achilles tenden was satisfactory. CONCLUSION: Latissimus dorsi myocutaneous flaps are the ideal choice for repairing local severe deep burn wounds.

Adult↗

PubMed2000

[Exploration of factors increasing transfer efficiency of retroviral mediated multidrug resistance gene (mdr1) into human CD(34)(+) cells].

OBJECTIVE: To explore factors influencing transfer of retroviral mediated multidrug resistance gene (mdr1) into human CD(34)(+) cells. METHODS: Transduction efficiency in the presence of different combinations of cytokines and human bone marrow stromal cells plus cytokines were determined by flow cytometry (FCM). Drug resistance was evaluated by plating yields of cultured hematopoietic progenitor cells. The effect of Taxol at different concentrations on mdr1 gene transfer cells was determined by FCM. RESULT: Transduction efficiency in the presence of SCF + FL + IL-3 was higher than that in other combinations of cytokines (SCF + IL-6 + IL-3, SCF + IL-6 + IL-3 + Tpo, SCF + IL-3). Transduction efficiency (20.5%) in the presence of bone marrow stromal cells plus cytokines (SCF + FL + IL-3) was higher than that (15.2%) without stromal cells, and the number of drug-resistant colony-forming cells was more in the former than in the latter. The percentage of CD(34)(+) cell with the gene transduction at 10 ng/ml Taxol reached 38.5%. CONCLUSION: Human bone marrow stromal cells plus cytokines (SCF + FL + IL-3) is more effective in enhancing mdr1 gene transduction. Taxol at a certain concentration can enrich mdr1 gene transferred cells.

Antigens, CD34↗

PubMed2000

[Experimental study on effect of bushen qingli huoxue treatment on glomerular extracellular matrix of remnant kidney in rats].

OBJECTIVE: To study the effect of Bushen Qingli Huoxue (BQH) treatment on glomerular extracellular matrix (ECM) and in retarding glomerular sclerosis in rats and to explore the mechanism and key of regulation. METHODS: Animal model was established by 5/6 nephrectomy and the study was carried out by using immune histochemical and pathological methods. Treatment of BQH started 1 week after operation. RESULTS: After being treated with BQH, the serum creatinine (SCr), blood urea nitrogen (BUN) and urinary protein excretion reduced markedly. Pathological examination showed accumulation of ingredients of glomerular ECM such as type I, IV collagen and laminin decreased significantly, the number of glomerular cells and proliferation cell nuclear antigen positive cells also decreased obviously, and showed that the glomerular sclerosis was retarded. The effect of BQH was similar to that of Enapril, but superior to that of Enapril in reducing BUN and SCr. CONCLUSION: BQH has the effects of reducing ECM accumulation, improving renal function and retarding glomerular sclerosis.

Animals↗

PubMed2000

[The change and distribution of endothelin-1 in lung of hypoxic pulmonary hypertension rat].

This study was aimed to determine the distribution and change of ET-1 in the lung of rat with chronic hypoxic pulmonary hypertension. Immunohistochemical analysis (Avidin-Biotion Complex) was used to localize the ET-1 immunoreactivity in the rat lung. The ET-1 concentration in plasma and in lung homogenate was measured by radioimmunoassay. In normal rats, the mean ET-1 concentration in venous plasma was 2.25 +/- 0.68 ng/L, in arterial plasma 1.52 +/- 0.63 ng/L and in lung 1.75 +/- 0.46 ng/L. There was no significant increase of ET-1 level in rats exposed to hypoxia for 2 hours, but there was significant increase of ET-1 after 24 hours hypoxia, and the high levels of ET-1 were maintained in the sustained hypoxia. There was significant correlation between the ET-1 level in arterial plasma(or in lung homogenate) and the maen pulmonary artery pressure. Similaryly, there was significant negative correlation between ET-1 in arterial plasma(or in lung homogenate) and PaO2. Immunohistochemical analysis revealed that the ET-1 immunoreactivity was seen in the endothelium of pulmonary arteries, particularly more positive staining was seen in the band between the endothelium and the smooth muscle cells. Chronic hypoxia elevated the mean pulmonary arterial pressure, caused vessel remodelling and the right ventricular hypertrophy. These changes were accompained by an increase of ET-1 in plasma and lung homogenate. The expression and production of ET-1 were localized to endothelium and airway epithelium in the lungs.

Animals↗

PubMed2000

[The study on the standardization of adults voice acoustic parameters by objective analysis].

OBJECTIVE: To explore the characteristic of normal voice in different age-bracket of Chinese adults and to formulate the normal reference value suited to our country at voice assessment. METHOD: We divided the adults into the youth, the middle-aged and the old groups, and analyzed normal voice samples with Dr. Speech software and computer multimedia technique and compared the following 5 parameters (Jitter, Shimmer, NNE, Fo and SDFo) of different groups divided according to one's age, sex and vowel. RESULT: There is difference among the group of age, sex and vowel in most acoustic parameters in the adults. CONCLUSION: To initiate taking multi-vowels samples and using different normal reference value and multi-parameters analysis according to the difference of age-bracket, sex and vowel in the adults.

Adolescent↗

PubMed2000

[Separation and determination of baicalin in prescriptions containing Scutellaria baicalensis Georgi by HPCE].

Qingkailing Oral Tonic and Shuanghuanglian Oral Tonic are two kinds of complex formlae of Chinese traditional patent medicine, and both contain Scutellaria baicalensis Georgi. Baicalin is referred to the main active component with functions of dispelling wind-heat to reduce fever and detoxicating, and takes effect on uppering respiratory tract infection and tonsillities. In this work a high performance capillary electrophoresis (HPCE) method was established for separation and quantitative analysis of baicalin in prescriptions containing Scutellaria baicalensis Georgi, based on the mode of capillary zone electrophoresis. Electrophoretic conditions are as follows: uncoated fused silica capillary (34.8/39.5 cm x 50 microns i.d.), 40 mmol/L borax buffer(pH 9.0), applied voltage 17 kV, polarity anode (inlet) to cathode (outlet), temperature 25 degrees C, detection wavelength 285 nm, injection 68.95 kPa x s. Under the optimum conditions, baicalin was separated successfully from other components within 15 minutes. The relative peak area of baicalin increased linearly with the increase of its concentration in the range of 10-640 mg/L. The recoveries were (100.31 +/- 1.98)% for Qingkailing Oral Tonic and (100.60 +/- 2.36)% for Shuanghuanglian Oral Tonic. The analytical results demonstrate the method is simple, rapid and well reproducible, and can be used as a reliable tool for the quality control of Chinese traditional medicines containing Scutellaria baicalensis Georgi.

Anti-Infective Agents↗

PubMed2000

[Determination of blood glucose by chemiluminescent flow-injection analysis with immobilized glucoxidase column].

Luminol-hemin system was used for chemiluminescent flow-injection analysis with immobilized glucoxidase(GOD) column to determine blood glucose. The method is fast, simple and sensitive. Blood samples were diluted to 1:1000 and pumped into the flow-injection analyzer for direct detection. The sampling frequency was 30 samples/h, with a detection limit of 7.2 x 10(-9) mol/L(1.30 micrograms/L). A column packed with 36 milligrams of CPG could be used nearly 200 times. The determination results of glucose in serum by this method were in good agreement with those obtained by the routine GOD spectrophotometric method (correlation coefficient r = 0.90, P > 0.05). Recoveries of this method were 94.0%-107.2%.

Blood Glucose↗

PubMed2000

[cDNA cloning and sequence analysis of the seventh segment of maize rough dwarf virus genome].

The double strand RNA of maize rough dwarf virus (MRDV) was prepared from the maize samples showing symptoms which was from the Luanchen county of Heibei province of China. The primers were designed according to the known sequence of MRDV, the cDNA sequence of the seventh segment of MRDV was obtained by RT-PCR, the S7 sequence was analyzed by computer after sequencing. The results showed: the full length of the S7 cDNA is 1936 bp and equal to that of the S7 cDNA from abroad, the two open reading frame(ORF1 and ORF2) contained in the S7 segment are also unchanged. In comparison with the S7 segment from Italy, the homology of S7 nucleotide is 87.7% and the homology of ORF1 amino acid sequence is 91.6%. However, the MRDV S7 segment and the rice black strike dwarf virus S8 segment showed 95.5% nucleotide identities and 93.5% ORF1 amino acid identities.

Amino Acid Sequence↗

PubMed2000

[Purification and characterization of cuticle-degrading protease from entomopathogenic fungus, Metarhizium anisopliae].

The cuticle-degrading proteases from entomopathogensis fungus, Melarhizium anisopliae, were induced by adding cicada exuviae, colloidal chitin, shrimp cuticle, maggot cuticle, horsefly cuticle and silkworm chrysalis cuticle into minimal medium. After ultrafiltration, Ultrogel AcA 54 column and IEF, a protease designated as MAP-21 with Mr 27 kD, and pI 7.6 were purified. It was shown that the recognition site of MAP-21 was Arg, PMSF and TLCK could inhibited the activity of this protease, indicating that there were Ser and His residues in the active center. The inhibitors to trypsin, leupeptin antipain and STI also repressed the activity of MAP-21, while chymostatin, TPCK and elastatinal TEI were shown no inhibition to its activity, demonstrating that, MAP-21 was a trypsin-like protease. Other properties of MAP-21 were also reported.

Enzyme Induction↗

PubMed2000

[Studies of adsorbents for hemoperfusion--preparation and in vitro studies of cross-linked agar beads entrapped Attapulgite clay].

A new method for preparation of cross-linked agar beads entrapped Attapulgite clay (CAA) is reported. Attapulgite clay was coated with agar and shaped in organic solvent, as well as cross-linked by epichlorohydrin. The products withstood autoclaving at 121 degrees C for 30 minutes and had a good adsorption ability for model compounds and medicines. The results of preliminary investigation indicate that CAA is relatively hemocompatible.

Adsorption↗

PubMed2000

[Zero-stress state of renal artery in spontaneously hypertensive rats].

By observing the opening angle of the renal artery, the zero-stress state of the renal artery was studied in spontaneously hypertensive rats (SHR) prior to and posterior to their hypertension, and the role of endogenous angiotensin II (Ang II) and endothelin (ET) on the zero-stress state was studied by giving SHR Losartan(AT1 receptor antagonist of Ang II) and BMS-182874 (an A type receptor antagonist of ET) respectively. The opening angle of the renal artery in SHR with established hypertension was much greater than that in wistar-Kyoto rats(WKY) (114.2 +/- 42.2 vs 70.2 +/- 30.4, P < 0.01). The opening angles of the renal artery in SHR treated with Losartan and BMS-182874 were much smaller than those in control SHR. The opening angles of the renal artery in Losartan-treated and BMS-182874-treated SHR were 65.9 +/- 32.7 and 66.6 +/- 41.54 respectively. The results suggest that non-unequal growth exists in the renal arterial wall in SHR with established hypertension and the residual stress and strain in SHR are greater than those in age-matched WKY. Endogenous Ang II and ET may play a role in the changes of zero-stress state in SHR with hypertension.

Angiotensin II↗

PubMed2000

[Study on the callus and cell culture of Hypericum perforatum].

Callus were induced from the leaves and stems of Hypericum perforatum L. The cell suspension culture and plate culture were also investigated in this paper. The results showed that the medium of MS which contained 2,4-D 1 mg/L and NAA 1 mg/L was the best one for inducing callus. The plant growth regulator of 2,4-D was assential for callus and suspension culture. Factors such as the time of cell suspension culture, the ways of plating and cell density, which affects the plating efficency were studied. The results showed that plating at density of 5 x 10(3) cells/ml and with monocells seperated from the cells cultured 14-21 days, high plating efficiency could be obtained either by conditional plate culture or by nursing plate culture.

Cell Culture Techniques↗

PubMed2000

[The Ahmed glaucoma valve implantation for refractory glaucoma].

OBJECTIVE: To evaluate the efficacy of the Ahmed Glaucoma Valve implant in the treatment of refractory glaucoma. METHODS: 28 cases(29 eyes) of refractory glacucoma were treated by the Ahmed glaucoma Valve implant, including 10 cases (10 eyes) of neovascula glaucoma, 5 cases (6 eyes) of juvenile glaucoma and 13 cases (13 eyes) of other causes glaucoma. RESULTS: Post-operative follow-up time was 3-12 months. The intraocular pressure (IOP) was lowered from preoperative 40.9 +/- 7.32 mmHg (1 mmHg = 0.133 kPa) to postoperative 20.63 +/- 2.75 mmHg in Neovascular glaucoma; from preoperative 41 +/- 5.66 to postoperative 18.00 +/- 2.12 mmHg in glaucoma after IOL implant combined with vitrectomy operation; from preoperative 33.65 +/- 5.28 to postoperative 16.45 +/- 1.48 mmHg in juvenile glaucoma; from preoperative 31.43 +/- 4.13 to postoperative 18.13 +/- 1.25 mmHg in the failure conventional filtering surgery of glaucoma. The postoperative complicatons were flat anterior chamber, hyphema, anterior iritis and so on. CONCLUSION: The Ahmed glaucoma valve implant is a useful method in lowing IOP of refractory glaucoma.

Female↗

PubMed2000

[Evaluation of polymerase chain reaction for detection of chlamydia trachomatis in eye swabs].

OBJECTIVE: To investigate the clinical value of Polymerase Chain Reaction (PCR) in the diagnosis of trachoma. METHODS: Direct amplication of 16S rRNA gene which is chlamydia-specific by PCR was used to detect chlamydia trachomatis (CT). RESULTS: Of 93 subjects who conformed to the diagnosis criteria of trachoma, 69 (74.2%) was PCR-Positive; Of 178 subjects who did not comform to the criteia, 6(3.4%) was PCR-positive. PCR had a sensitivity of 74.2% and a speciticity of 96.7% for the clinical diagnosis of trachoma. The difference between trachoma group and nontrachoma group is significant(P < 0.001). CONCLUSION: The PCR may be a good method in the diagnosis of ocular chlamydia trachomatis infection because of its excellent sensitivity and specificity.

Adolescent↗

PubMed2000

[Precise map of allelic loss on chromosome 3p14 in nasopharyngeal carcinoma].

OBJECTIVE: To determine the precise allelic loss on chromosome 3p14 and discuss the possible relations between loss of heterozygosity (LOH) and EBV infection, clinical stage and clinic-pathology of nasopharyngeal carcinoma (NPC). METHODS: Six high dense microsatellite marker on chromosome 3p14 were selected to examine LOH in 32 cases of NPC. RESULTS: 23 of 32 (71.9%) tumors were deleted for at least one locus of six loci. High frequencies of LOH (> 40%) were observed at loci D3S1300(50.0%), D3S1313(46.4%) and D3S1312(44.4%). 12 cases showed LOH in one contiguous and nonrandom region. The smallest common deletion region seems likely to lie between D3S1313 and D3S1312. Relations between LOH on 3p14 and clinical stage and EBV infection were observed. The frequency of LOH was 70.0% in 30 cases of poor-differentiated squamous cell carcinoma. 2 cases of vesicular nucleus cell carcinoma had LOH at two loci. CONCLUSION: The high deletion rate on 3p14 in NPC indicates that there might be a putative tumor suppressor gene related to the development and progression of NPC.

Alleles↗

PubMed2000

[Transposition of expanded cervical-shoulder skin flaps for the repair of cicatricial contracture deformity of neck].

OBJECTIVE: To evaluate the efficacy of expanded cervical-shoulder skin flap in the treatment of cicatricial contracture deformity of neck, and improve the method for the repair of soft tissue defect of neck. METHOD: 12 patients with cicatricial contracture of neck were treated by pre-expanded cervical-shoulder skin flap and then transposition for the reconstruction of the defect after cervical scar resection. RESULT: All the 24 flaps were survived. Postoperative follow-up for 6 months to one year showed that the cervico-mandibular function and the external appearance of the flaps were satisfactory without swelling and contracture. CONCLUSION: Pre-expanded cervical-shoulder skin flap is available for the treatment of cicatricial contracture deformity of neck.

Adolescent↗

PubMed2000

The role of hysterectomy in the therapy of gestational trophoblastic tumor.

OBJECTIVE: To evaluate the role of hysterectomy for patients with gestational trophoblastic tumor. METHODS: We retrospectively analyzed 68 cases of gestational trophoblastic neoplasia treated by hysterectomy from 1985 to approximately 1997 at PUMC hospital. Thirty-eight cases were diagnosed of choriocarcinoma and 30 were invasive mole. RESULTS: Twenty-three elder patients who didn't desire to preserve fertility were selected for hysterectomy after shorter courses of chemotherapy, 22 of them had a complete remission (95.6%), the total average courses of chemotherapy was 4.2. Of twenty-seven chemorefractory cases who were suspected of a refractory isolated lesion in the uterus, delayed hysterectomy as an adjunct to chemotherapy was performed, 20 of them got a complete remission (71.1%), the total average courses of chemotherapy were 9.4. Emergency hysterectomy is indicated in 18 patients with uterine perforation or life-threatening hemorrhage, 17 cases had a complete remission (94.4%), the total average courses of chemotherapy were 7.6. CONCLUSION: Although the development of effective chemotherapy has resulted in improved survival of patients with gestational trophoblastic tumor, hysterectomy remains an important adjuncts in the treatment of a selected subset of patients; in order to operate more completely and prevent recurrence, it's better to perform extended hysterectomy for the indicated patients.

Adult↗