Background Researches showed that platelet-derived growth factor (PDGF) modulate the expression of matrix metalloproteinase/tissue inhibitor of metalloproteinase (MMP/TIMP) in cells,but the association of expression of MMP/TIMP in retinal pigment epithelial (RPE) cells and the dose and active time of PDGF is unclear.Objective This study was to observe the effects of PDGF on the expressions of MMP-2,MMP-9 and TIMP-1 in cultured RPE cells in vitro.Methods RPE cell line,ARPE-19,was calculated in vitro,and the cells were divided into 5 groups when they reached 70％-80％ confluence.Different concentrations (0,0.1,1,10,50 mg/L) of PDGF was added into the medium respectively for 36 hours,and the expressing levels of mRNA and protein of MMP-2,MMP-9 and TIMP-1 were detected by reverse transcription PCR (RT-PCR) and Western blot assay.In addition,RPE cells in PDGF group were treated with 10 mg/L PDGF for 24,36,48 hours respectively to detect the expressions of mRNA and protein of MMP-2,MMP-9 and TIMP-1 in the cells and to compare with the control group without PDGF.Results PDGF stimulated proliferation of RPE cells in a dose-and time-dependent manner.As the increase of the PDGF concentrations,the expression values of MMP-2 mRNA and MMP-9 mRNA in RPE cells were gradually elevated,with a statistically significant difference among various groups (MMP-2 mRNA:F=79.304,P=0.000;MMP-9 mRNA:F =8.465,P=0.003),and the expressions of MMP-2 mRNA and MMP-9 mRNA were significantly higher in the 1,10,50 mg/L PDGF groups compared with 0 mg/L PDGF normal control group (all at P＜0.05).Also,the expression values of MMP-2 and MMP-9 proteins in RPE cells were gradually elevated with the increase of PDGF concentrations,showing statistically differences among the groups (MMP-2:F=26.550,P=0.000;MMP-9:F=80.993,P=0.000).Compared with the 0 mg/L PDGF group,MMP-2 and MMP-9 expression levels in the 1,10,50 mg/L PDGF groups were significantly up-regulated (all at P＜ 0.05).However,the expression levels of TIMP-1 mRNA and protein group in the cells were not significantly different among various groups (mRNA:F =0.143,P =0.962 ; protein:F =1.955,P =0.178).The expression levels of M MP-2 mRNA,M MP-9 mRNA in the cells were increased in the PDGF group compared with the control group at different time points (MMP-2 mRNA:Ftime =83.250,P=0.002 ; MMP-9 mRNA:Ftime =6.785,P =0.019).Also,the expression values of MMP-2 and MMP-9proteins in RPE cells were increased in the PDGF group compared with the control group at different time points (MMP-2:Ftime =1 l.185,P =0.041 ; MMP-9:Ftime =968.413,P =0.000).The expression levels of MMP-2 and MMP-9 mRNAs and proteins were significant between the two groups at different time points (all at Pgroup =0.000;all at Ptime＜0.05).While the expression changes of TIMP-1 werc not significant between the two groups and among various time points (all at P＞0.05) Conclusions PDGF up-regulates MMP-2 and MMP-9 expressions in RPE cells in a dose-and time-dependent manner.But,PDGF dose not alter the expression of TIMP-1.These results indicate that PDGF disrupt the balance of MMP/TIMP,which may damage the extracellular matrix and therefore facilitate the migration of RPE cells in the pathogenesis of proliferative vitreoretinopathy.

OBJECTIVETo analyze the clinical and laboratory characteristics of Gitelman syndrome.

METHODSSeventeen patients with Gitelman syndrome (male/female: 11/6) were analyzed for their clinical symptoms, laboratory test results, imaging findings, treatments and outcomes.

RESULTSFifteen of the 17 patients presented with varying degrees of lower limb weakness, and 8 experienced flaccid paralysis. The laboratory tests showed hypokalemia (17/17), hypomagnesemia (17/17) and hypocalcemia (17/17). Blood renin activity (17/17), angiotensin II (14/17) and aldosterone levels (7/17) were significantly higher in the patients than in normal subjects. The symptoms were relieved by potassium alone or in combination with indomethacin, spironolactone and other potassium magnesium asparaginate, but the serum potassium and magnesium failed to recover the normal levels after the treatments.

CONCLUSIONThe primary clinical manifestations of Gitelman syndrome are lower extremity weakness with hypokalemia and hypomagnesemia. Combined drug therapies including potassium, magnesium, aldosterone antagonists and other drugs are recommended. The prognosis of the patients is favorable.

Adolescent ; Adult ; Child ; Female ; Gitelman Syndrome ; diagnosis ; drug therapy ; Humans ; Indomethacin ; therapeutic use ; Male ; Middle Aged ; Potassium Chloride ; therapeutic use ; Potassium Magnesium Aspartate ; therapeutic use ; Retrospective Studies ; Spironolactone ; therapeutic use ; Young Adult

OBJECTIVETo explore a way of determining the weights of variables in synthetic evaluation.

METHODSBased on the attribute synthetic evaluation system, similarity weight was used to cluster and rank the atmospheric quality on 11 large cities.

RESULTSRealized the classification and ranking for the atmospheric quality of the cities given, the results were almost comparable to that achieved by Topsis evaluation.

CONCLUSIONThe method of comprehensive assessment using similarity weight in the attribute synthetic evaluation system seemed to be objective and rational. Not only it embodied the weights of variables involved, but also exploiting the information presented by the sample.

Air Pollution ; prevention & control ; statistics & numerical data ; China ; epidemiology ; Data Interpretation, Statistical ; Decision Making ; Environmental Monitoring ; Epidemiological Monitoring ; Evaluation Studies as Topic ; Humans ; Models, Theoretical

AIMTo establish a capillary zone electrophoresis (CZE) method for determination of thymulin in human blood plasma. Thymulin is a nonapeptide produced by the thymic epithelium.

METHODSThe uncoated capillary used was 75 microns ID x 57 cm (50 cm effective length). The experimental conditions were as follows: the running buffer was phosphate-borate buffer containing 50 mmol.L-1 Na2B4O7-10 mmol.L-1 Na2HPO4 (pH 9.10); running voltage was 12 kV; operated temperature was 25 degrees C; running time was 13 minutes, detective wavelength was 200 nm.

RESULTSThe linear range of the thymulin standard curve was 1-10 micrograms.mL-1, gamma = 0.9990, the average recovery was 70.97% with RSD of 3.32%, the RSD of reproducibility was 3.05%.

CONCLUSIONThe method of CZE for determination of thymulin in human plasma is simple and reliable.

Child, Preschool ; Electrophoresis, Capillary ; Humans ; Plasma ; chemistry ; Thymic Factor, Circulating ; analysis

Objective To investigate the possible role of interstitial cell of Cajal (ICE)in the pathogenesis of diabetic gastroparesis and the protective effect of"Xiaopi prescription (消痞方)".Methods Fifty healthy male Spregue-Dawley (SD) rats were randomly divided into 5 groups (each n=10):normal, model,and 3 Xiaopi prescription groups:low,middle and high dosages.Diabetes was induced by intravenous injection of alloxan,and equal amount of normal saline was intravenously injected in the normal group.Gastric lavage method was used to administer the traditional Chinese medicine decoction of Xiaopi prescription in corresponding amount (5,10 and 20 g?kg~(-1)?d~(-1)) in respective low,middle and high dosage groups.In the normal control group and diabetic model group,only equal amount of normal saline was administered into the stomach.Gastric emptying rate was measured by method of nutritious semisolid paste;c-kit positive cells of ICC were quantitatively measured with immunohistochemistry assay and computer image analysis system;c-kit mRNA positive cells were quantitatively measured with in situ hybridization and computer image analysis system.Results①Gastric emptying rate:The rate was significantly lower in the model group than that in the normal control group (P0.05),but higher than those in the model group and the low dosage group (all P0.05).②c-kit immmunohistochemistry:c-kit positive cell presented yellow in color,and its membrane was stained yellow,this kind of cells primarily were distributed around the neural plexus in the inter-space between the circular and longitudinal muscular fibers, and around the ganglionic cells forming"sheath-like"structure.The results of numbers of c-kit positive cells in the various groups:the number of the cells in the model group was significantly lower than that in the normal group (P0.05),but the numbers in the former two dosage groups were obviously higher than those in the model group (all P0.05),being significantly lower than that in the normal group,middle and high dosage groups (all P0.05),but obviously higher than those in the model group (all P0.05),being significantly lower than that in the normal,middle and high dosage groups (all P

OBJECTIVETo explore the epidemiological status and risk factors of hyperuricemia in rural area of the Three Gorges.

METHODSA cross-sectional survey was carried out in rural area of Yiling District, Yichang City, which was located north-west bank of Xiling Gorge in 2007. A standard structure questionnaire was used to collect demographic data, social-economic status and life-style features. Fasting venous blood was collected and serum uric acid (SUA) was determined. Hyperuricemia was defined as SUA levels ≥ 417 µ mol/L (70 mg/L) in men and ≥ 357 µmol/L (60 mg/L) in women. Multiple logistic regression analysis was used to analysed the risk factors of hyperuricemia.

RESULTSA total of 9354 participants aged 35 and above were included, 19.9% (1866/9354) participants were the Three Gorges migrants. Serum uric acid level in men was significantly higher than that in women [(285.1 ± 80.2) µmol/L vs. (210.3 ± 65.0) µmol/L,P < 0.01].Serum uric acid level increased significantly in both genders in proportion to increase of age, and was higher in men than in women in all age groups (all P < 0.01). The age-adjusted prevalence was significantly higher in men than in women (5.6% vs. 3.3%, P < 0.01), and was also higher in men aged 35-44 and aged 45-54 than in women (both P < 0.01). There was no significance in prevalence of hyperuricemia in both men and women aged 55-64 and aged ≥ 65. After adjusting age, gender, educational level, migration and occupation, the multiple logistic regression analysis showed that the prevalence of hyperuricemia was higher in alcohol drinking participants than that of non-alcohol drinking participants (OR = 2.06, 95%CI:1.59-2.67, P < 0.01), and in participants used to consume less green vegetables and fruits than in participants consuming more green vegetables and fruits (OR = 1.77, 95% CI:1.27-2.47, P < 0.01).

CONCLUSIONSThe prevalence of hyperuricemia is relatively low in rural area of the Three Gorges.Alcohol drinking and low intake of green vegetables and fruits are the risk factors of hyperuricemia in this population.

Adult ; Aged ; China ; epidemiology ; Cross-Sectional Studies ; Female ; Humans ; Hyperuricemia ; epidemiology ; Logistic Models ; Male ; Middle Aged ; Risk Factors

OBJECTIVETo investigate the feasibility of life span extension of transformed human embryonic tendon cells (THETC) by reconstitution of the telomerase activity.

METHODSTHETC were transfected by pGRN145 plasmid containing the human telomerase reverse transcriptase (hTERT) cNDA in vitro by molecular cloning technique. The biological characteristics of transfected cells were detected and compared by morphological observation, plate cloning efficiency, soft agar culture, growth curve of cells cultured in different conditions, immunohistochemistry, telomerase activity assay by telomeric repeat amplification protocol (TRAP).

RESULTSThe THETC transfected by pGRN145 plasmid (telT) could express the telomerase activity with extension of life span. The telT maintained the original characteristics of temperature-dependant and serum-dependant, as well as secretion of type I collagen normally and without tendency of malignant transformation.

CONCLUSIONSThe life span of THETC can be prolonged by reconstitution of telomerase activity, which provides the novel experimental methods to establish the standard cells line.

Cell Line ; Cell Survival ; Embryo, Mammalian ; Humans ; Plasmids ; genetics ; RNA-Directed DNA Polymerase ; Telomerase ; genetics ; metabolism ; Tendons ; cytology ; enzymology ; Transfection

Multi-stage countercurrent extraction technology, integrating solvent extraction, repercolation with dynamic and countercurrent extraction, is a novel extraction technology for the traditional Chinese medicine. This solvent-saving, energy-saving and high-extraction-efficiency technology can at the most drive active compounds to diffuse from the herbal materials into the solvent stage by stage by creating concentration differences between the herbal materials and the solvents. This paper reviewed the basic principle, the influence factors and the research progress and trends of the equipments and the application of the multi-stage countercurrent extraction.
Countercurrent Distribution ; methods ; Drugs, Chinese Herbal ; isolation & purification ; Particle Size ; Plants, Medicinal ; chemistry ; Solvents ; chemistry ; Technology, Pharmaceutical ; instrumentation ; methods ; Temperature ; Time Factors

Recent studies have been raising doubts on the safety of induced pluripotent stem cells (iPSCs) and proposing that the process of reprogramming brought about copy number variations (CNVs) in iPSCs. However, a recent paper published in Nature provided evidence showing that most CNVs were pre-existed as somatic mosaicism but not resulted from the reprogramming. This new finding would profoundly reshape some previous thoughts and endorse the confidence of iPSCs in both research and therapy.
Cellular Reprogramming ; DNA Copy Number Variations ; Humans ; Induced Pluripotent Stem Cells ; metabolism ; Mosaicism ; Regenerative Medicine