Biomedical subjects
Publications and source records attributed to Z Chen.
The single-chip microcomputer technique is used in the present study of spinning counter, which has 4 observation tunnels, the spinning behave of four experiment animals can be recorded at same time. The function of this instrument has four selections according to different experiment, and the recording data can be compute processed.
PURPOSE: Neuron-specific enolase (NSE) of containing gamma-enolase is considered valuable in the diagnosis of tumours of neuroectodermal origin. METHOD: We used rapid electrophoretic method on cellulose acetate plate to determine the pattern of enolase isoenzymes in 21 aqueous humor and 23 serum specimens from retinoblastoma (Rb) and 21 aqueous and 25 serum specimens from 25 control cases to evaluate NSE in the diagnosis of Rb. The assay allowed assessment of all three major isoenzymes (alpha alpha, alpha gamma and gamma gamma), and NSE relative activity and its percentage in the total relative activity of the three enolase isoenzymes were assessed by means of fluorometer. RESULT: Aqueous from all patients with Rb contained alpha alpha, alpha gamma and gamma gamma isoenzymes and presented strong positive, the positive rate of NSE being 100% and its relative activity accounting for 45 +/- 9% of the total relative activity of the 3 enolase isoenzymes; No enolase was detectable in control aqueous with cataract, glaucoma and Coats's diseases (4 cases), but in two patients with traumatic hyphema alpha alpha and faint alpha gamma and gamma gamma were presented in aqueous. The control serum contained only an alpha alpha band, while the sera form patients with Rb contained alpha alpha, alpha gamma and gamma gamma bands in 18 of 23 specimens, the positive rate being 78.2%, and only alpha alpha bands in the rest 5 specimens (21.8%). In patients with Rb, the NSE relative activity and its percentage in the total relative activity of the 3 isoenzymes in serum (36 +/- 9%) were significantly lower lever than those in aqueous. CONCLUSION: The amounts of NSE increase significantly in both serum and aqueous from patients with Rb, and the immunoelectrophoretic assay for determination of enolase patterns is valuable in the diagnosis of Rb and differential diagnosis of Rb. In addition, the method is rapid, simple and requires only a little amount (< 5 microL) of samples.
PURPOSE: To observe the results of intraocular lens implantation in diabetics who suffered from cataract. METHODS: 30 cases (37 eyes) of diabetics with cataract and 174 cases (197 eyes) of non-diabetics with senile cataract were performed with intraocular lens implantation. The postoperative follow-up was from 2 to 18 months. RESULTS: The statistics of the visual acuity in two groups had no difference. The primary factor that effected visual acuity was original retinopathy. Postoperative complications of diabetics group, such as anterior chamber fibrinous exudate, pigment diffusion, were much serious than those of non-diabetic group. But if strong effective hormones were locally administrated, inflammation was absorbed. CONCLUSION: The therapeutic results of the diabetics with no or only minor retinopathy were similar with those of non-diabetics.
A pair of oligonucleotide primers were designed to amplify the endoflagella gene of L. interrogans serovar lai. An approximately 840 bp fragment was generated with PCR and inserted into plasmid pUC8, after the fragment and pUC8 were digested respectively with BamHI and PstI. A recombinant plasmid (designated as pLF1) was obtained. SDS-PAGE analysis indicated that a 33 kDa was expressed in E. coli JM103 harboring pLF1 and the expression level of the protein was 11% of the total bacterial soluble proteins. Western blot analysis showed that the protein band could be recognized by the antiserum against the endoflegella (Axial filament) of Leptospira interrogans serover lai. Nucleotide sequence data showed an open reading frame encoding 282 aminoacids residues, corresponding to a protein of molecular weight 33.6 kDa. Comparison of the deduced endoflagellar subunit protein (flaB) amino acid sequence with flagellins from other bacteria revealed a high level of identity with the Treponema pallidum flaB proteins. Immunization/protection experiment was performed on the model of BALB/C mice and showed that there was higher survival rate in the group JM103-pLE1 than in the group JM103-pUC8.
A convenient method for quantitative analysis of the nucleosides in Fritillaria bulbs has been developed by means of thin layer chromatography and ultraviolet spectrophotometry. The MeOH extracts from four species of Fritillaria were analyzed with this method. The results show that both adenosine and thymidine in the four species are quite disparate, suggesting that the nucleosides may be responsible for the anti-coagulative activity of Fritillaria.
In order to describe the magnetic resonance imaging (MRI) findings in hypothalamic-pituitary area and its clinical relevance in patients with idiopathic growth hormone deficiency (IGHD), the MR imagings of 26 patients with IGHD were analyzed. On MRI, 24 out of 26 cases (92.3%) showed apparent pituitary upper margin depression; 8 out of 26 cases (30.8%) showed definite pituitary stalk transection; 22 out of 26 cases (84.6%) showed absence of the normal posterior pituitary bright spot. The bright lipidlike signal on T1W1 images at the median eminence distal to the breaking point (so-called ectopic posterior lobe) was found in 4 out of 26 cases (15.4%). According to the MRI findings of the pituitary stalks, the 26 cases were divided into three groups; group A of 8 cases (31%) characterized by the definite transaction of stalk; group B of 13 cases (50%) defined by the possible stalk transection; and group C of 5 cases (19%) with no definite stalk transection. MRI findings were consistent with the clinical and endocrine tests. The stalk transection was statistically significantly difference in insulin test, L-dopa/p test, and height standard deviation score (P < 0.05). The MRI of hypothalamic-pituitary area may differentiate partial IGHD form stalk-transected, doubtful transection and without transection.
A no-mix orthodontic adhesive composed of primer and paste was developed. The adhesive eliminated the spatulation procedure to which most commercially available products were imperative, could quickly polymerize and cure by means of contact and slight compression of the primer with the paste. It featured high bond strength, convenient handling, enough working time, easy removal of extra adhesive around the bracket and no objectionable odour. The biological tests showed it was safe to use in orthodontic practice, and the results of clinical trials certified the reliable performance, effective bond and convenient use of the adhesive.
Four kinds of substitutive materials for hard tissues were inserted into tibias of rat, effect of substitutive materials on IGF-I mRNA expression level of cell in the interfaces of bone and four kinds of substitutive materials were studied by the technique in situ hybridization. It showed that the biomaterials could affect the level of IGF-I mRNA expression, the enhanced expression level was associated with cell proliferation, formation of matrix and calcification, formation of new bone. Measurement of IGF-I mRNA could attribute to judge the functional state of cell, and to predict the final character of the interface.
The authors studied the expression level of IGF-I mRNA of osteoblasts cultured from the rats' calvarias, affected by four kinds of substitutive materials for bone tissues, using the technique in situ hybridization. The result showed that the substitutive materials could affect the expression level of IGF-I mRNA of osteoblasts. The measurement of expression regulation may be a parameter for evaluation of biocompatibility of substitutive materials for bone tissues.
The implant materials chosen in this study included hydroxy-poly (calcium natrium phosphate), hydroxyapatite, bioglass ceramic and Ti-6Al-4V. The implants were inserted into the mandibles of dogs. The samples from dogs were regularly observed by X-ray examination, optical microscope, scanning electron microscope and X-ray energy spectrograph. The results showed that all the implants had integrated into the surrounding bone tissue by the third month. During the early stage of the experiment, there were a lot of S, Si at the bone-implant interface. After new bone became mature, the contents of Ca, P increased, but the contents of S, Si decreased at the interface.
Phosphoric acid esters can be used as restorative materials for human teeth and bones. The authors investigated bonding performance of phosphoric acid diester (DPR) with tensile bond test. The results showed: (1) DPR dental adhesive could markedly improve the tensile bond strength (TBS) to human enamel, dentin, dental nonprecious metals and self-curing denture plastics, it is used widely; (2) Three kinds of the etchants could also improve markedly TBS. 37% phosphoric acid and DT-I were respectively applicable to enamel and dentin. DT-II was available to both of them.
The aim of present study is to assess the effect of complete denture relining on the electromyogram of masticatory muscles. The electromyography and the computer-EMG system were used for collecting and processing bilateral masseter and anterior temporal muscles activities before and after denture relining. The results showed that the mean myoelectric potentials of the masticatory muscles was increased during chewing and maximal biting when the dentures were relined. The conclusion was that the level of the masticatory muscle activity was increased when a clinically acceptable occlusal vertical dimension was obtained by using relining method.
Osteoblasts were isolated from Sprague Dawley rats of 1-3 days on the frontal parietal bones and were confirmed by testing for multiple biological features. The results showed that rat osteoblasts in vitro had the same morphological feature, ALP activity, the function of synthetic BMP as in vivo and it had the ability of calcification in vitro. The results proved that these rat osteoblasts in vitro had the same function and features as in vivo and it could be used to study cytocompatibility on replacement materials of human body's hard tissues and biomedical to make experiments related to bone tissues.
By means of polyacrylaminde gel eletrothoresis and thin layer scanning, the paper semi-quantitatively studies some relation between component and activity of isoenayme of Ginseng infecting red skin desease. The results show activity of esterase increases 100% than that of normal Ginseng; activity of polyphenol oxidase increases 60-30% and represent new isoenzyme bands in the early infection in juxtapose transolant experiment.
Ampelopsis cantoniensis (Hook. et Arn.) Planch. is a Chinese herbal medicine rich in flavonoids. A method to determine flavonoids in the herbal was studied. After the herbal was extracted in hot water, Ampelopsin and myricetin in the extract were separated by polyamide column with eluent of ethanol-water and measured by spectrophotometry. As results, 100 g of the dry herbal contains 25.2 g of ampelopsin (RSD = 1.7%, recovery = 97.0%) and 1.77 g of myricetin (RSD = 3.3%, recovery = 103%).
The constituents of the essential oil in leaves of Torreya nucifera (L.) Sieb. et Zucc. (EOLTN) in China were firstly analysed by GC-MS-DS. 68 of the 71 separated constituents in EOLTN were identified. The total contents of identified constituents accounted for 96.364% of EOLTN.
For exploring cellular immunity disturbances in children with acute lower respiratory infection (ALRI) caused by respiratory syncytial virus (RSV) the level of interleukin-2 (IL-2) soluble interleukin-2 receptor (sIL- 2R), the expression rate of interleukin-2 receptor (IL-2R) on T cells and percentage of T lymphocyte subsets were determined in peripheral blood of 25 acute cases. The results showed that compared acute stage of RSV associated ALRI with recovery stage and control group, the level of peripheral blood IL-2 and expression rates of IL-2R decreased but the level of sIL-2R increased. The level of IL-2 had positive correlation with IL-2R and percentage of CD4+ cells, but had negative correlation with sIL-2R and percentage of CD8+ cells. The plasma sIL-2R level had negative correlation with expression rate of IL-2R, but had a positive correlation with clinical severity. These results suggested that human body had a functional disturbance in cellular immunity when infected with RSV.
The separation of stereoisomers of 14 pyrethroids has been studied by capillary gas chromatography. The pyrethroids are cypermethrin (P1), phenothrin (P2), allethrin (P3), prallethrin (P4), tetramethrin (P5), permethrin (P6), cyfluthrin (P7), fenvalerate (P8), flucythrinate (P9), bromofenvalerate (P10), fluvalinate (P11), methothrin (P12), resmethrin (P13) and py115 (P14). The gas chromatographic conditions were as follows. Column 1: fused silica, 10m x 0.53mm x 1.0microm film (QF-1); columntemperature: 180 degrees C-260 degrees C depending on the pyrethroids analysed; the temperature of injector and detector: 280 degrees C; carrier gas: H2 4.6mL/min; detector: FID; spilt ratio: 5:1, sample size 1.0 L. The stereoisomers of P2, P3, P4, P5, P6, P8, P9, P10, P12 and P10 can be completely separated by QF-1 column. However the stereoisomers of P11 can not be separated and the three peaks of P1 and P7 have been only separated by column 1. In comparing with packed column of QF-1, there are advantages in superior resolution, lower oven temperature and shorter analysis time for capillary column of QF-1. Column 2: fused silica HP-5 (crosslinked 5% phenyl methyl silicone) 25m x 0.32mm x 1.0microm film; column temperature: P1 and P7 250 degrees C, P11 260 degrees C, and P14 200 degrees C; carrier gas: H2 2.6mL/min. Other conditions were the same as the column 1 described. The stereoisomers of P1, P7, P11 and P14 can be separated, but the separation of stereoisomers was not sufficient. The stereoisomers of P2, P5, P6, P8, P9, P10, P12 and P13 can be completely separated by HP-5 capillary column. However separation on the HP-5 capillary column is not sufficient for diastereoisomers of P3 and P4.