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Biomedical subjects

M Zhang

Publications and source records attributed to M Zhang.

At least 415 records · Page 23Linked to original sources
PubMed2000

[Construction, eukaryotic expression and biological activities of a recombinant human single chain interleukin-12 fusion gene].

OBJECTIVE: To explore the feasibility of recombinant human interleukin 12 (IL-12) with biological activities by molecular biological techniques. METHOD: Both p40 and p35 subunits cDNA of human IL-12 were cloned from mRNA extracted from NC-37 cell line by using RT-PCR, and the fusion gene (p40-linker-p35) of recombinant human single chain IL-12 (rhscIL-12) was constructed by using a polypeptide linker (Gly(4)Ser)(3). rhscIL-12 eukaryotic expressing vector pcDNA3.1 (+)-hscIL-12 was constructed by inserting the rhscIL-12 fusion gene into pcDNA3.1 (+) eukaryotic expressing plasmid. COS-7 cells were transfected with pcDNA3.1 (+)-hscIL-12 plasmid. RESULT: A stable rhscIL-12 expressing cell line COS-rhscIL-12 was obtained by G418 selection. Western blot showed the presence of a 70 x 10(3) band of the fusion protein, which specifically bond to mouse-anti-human IL-12 monoclonal antibody. The assays of biological functions showed that the fusion protein had strong bioactivities in stimulating the lymphocyte proliferation, enhancing the NK cell cytotoxicity and increasing the IFN-gamma production. CONCLUSION: The constructed rhscIL-12 fusion gene could express biologically functional rhscIL-2 fusion protein.

Animals↗
PubMed2000

[Role of nitric oxide in the reflex of raising biliary pressure].

Raising the biliary tract pressure from the baseline to 4 kPa significantly decreases arterial blood pressure and myoelectric activity of sphincter of Oddi (SO) (bile duct-arterial blood pressure reflex), which is sometimes associated with the disappearance of phasic myoelectric activity of SO (bile duct-SO reflex). Thirty-two rabbits were used to investigate the role of nitric oxide (NO) in these reflexes. On the base of increased myoelectric activity and arterial blood pressure by intravenous drip of 4 microgram/(kg.min) noradrenaline, raising the biliary tract pressure from the baseline to 4 kPa significantly decreased arterial blood pressure and myoelectric activity of SO. On the base of increased myoelectric activity and arterial blood pressure by intravenous injection of 10 mg/kg L-NNA, the bile duct-arterial blood pressure reflex disappeared in all the rabbits, but the bile duct-SO reflex disappeared only in a population of (3/8) and obviously decreased in the remaining ones (5/8) during raising biliary pressure from the baseline to 4 kPa. The bile duct-SO reflex after preceding local perfusion of L-NNA was similar to that after preceding intravenous injection of L-NNA, but bile duct-arterial blood pressure reflex still appeared. These findings suggest that both of these two reflexes are caused by the tension stimulation to the receptive area of the biliary tract, and may be mediated by NO.

Animals↗
PubMed2000

[Relationship between the alteration of 6-keto-PGF1 alpha and TXB2 in cervical mucus of patients with threatened preterm labor and the efficacy of magnesium sulfate treatment].

This study was conducted to observe the relationship between the alteration of 6-keto-PGF 1 alpha and TXB2 in cervical mucus of patients with threatened preterm labor and the efficacy of magnesium sulfate treatment, and to examine whether they could act as markers of efficacy and prognosis in treatment of preterm labor. Cervical mucus was collected from 28 patients with threatened preterm labor before and after magnesium sulfate treatment, the levels of 6-keto-PGF1 alpha and TXB2 were determined by radioimmunoassay (RIA). The results showed that the levels of 6-keto-PGF1 alpha and TXB2 decreased in patients successfully treated with magnesium sulfate (P < 0.01), and the ratio of 6-keto-PGF1 alpha to TXB2 increased significantly (P < 0.001). The levels of 6-keto-PGF1 alpha and TXB2 increased in patients with failed magnesium sulfate treatment (P < 0.01), and the relevant ratio decreased significantly (P < 0.001). The results indicate that the levels of 6-keto-PGF1 alpha and TXB2 in the cervical mucus of patients with threatened preterm labor may change significantly before and after magnesium sulfate treatment and they could be used as markers of efficacy and prognosis in treatment of preterm labor.

6-Ketoprostaglandin F1 alpha↗
PubMed2000

[Effects of sulpiride on morphine-induced reward and its relation to cyclic AMP levels in mice].

This study examined the effects of sulpiride, a dopamine D2 receptor antagonist, on morphine rewarding properties and its relation to cyclic AMP levels in brain. The morphine-induced reward in mice was observed in a conditioned place preference test. Cyclic AMP was estimated by radioimmunoassay. The time of staying in morphine pairing compartment and the cAMP levels in brain of mice in the morphine group increased as compared with those in other groups (P < 0.05), but there was no significant difference in the time of staying in morphine pairing compartment and the cAMP levels in brain between the saline group and the sulpiride plus morphine groups (P > 0.05). These suggest that the inhibition of morphine-induced reward by sulpiride be due to the prevention of an increase in cyclic AMP levels in brain.

Animals↗
PubMed2000

[Cloning and tissue expressive pattern analysis of the human ribosomal S6 kinase-RPS6KA5 cDNA].

Human ribosomal protein S6 kinase includes two protein families: P90RSK and P70S6K, they participate in two different signaling pathways. When the two kinases were inhibited by their antibodies or rapamycin, the proliferation of cells was arrested. However, their analog, the immunosupressant FK-506, can inhibit the proliferation of fibroblast PBL1 without interfering with the activities of P90RSK, P70S6K and MAPK. We take the tactics of "homolog screening" to demonstrate whether there are some novel proteins which can substitute for the known P90RSK and P70S6K or other pathways without interfering with the known P90RSK and P70S6K. With the conserved sequence of mouse p90RSK as a probe, we screened the homologous sequence in NCBI EST database and got three human EST fragments. With the assembled contig as a probe to screen human brain cDNA library, a full-length cDNA of 3833 bp was attained. It contains a completed open reading frame from 165 bp to 2570 bp encoding 802 amino acids. The putative protein has higher homology with other members of p90RSK family. The gene was named RPS6KA5, the accession number in GenBank is AF090421. Northern hybridization showed the gene expressed in 16 human tissues tested, and the gene was localized in 14q31-32.1 by RH mapping. Another novel P70S6K gene has also been cloned. Thus, our initial presumption that there is an analog of known P90RSK and P70S6K in human beings was proved.

Amino Acid Sequence↗
PubMed2000

[Studies on the Robertsonian translocation of Microtus mandarinus].

The type of chromosome No. 1 and chromosome number from 53 individuals of Microtus mandarinus have been studied and compared in three sex types: XY, XX, XO. We found that the first pair of autosomes are very unstable, and there are three types: (1) M, M (With a double metacentric chromosome), (2) M, T, T, (With single metacentric chromosome). (3) T, T, T, T (Without metacentric chromosome). The chromosome number of the same sex individuals changes regularly with the type change of chromosome No. 1, that is, the increase of one chromosome in 2n number is always accompanied by the increase of two T and the decrease of one M, and vice versa. The synaptonemal complexes (SCs) of spermatocyte in pachytene nuclei from the males (2n = 51) were analysed by the electron microscopy. The SCs studies demonstrate that there are 23 fully paired autosomal bivalents, XY-bivalent and an autosomal trivalent. This trivalent is formed by one metacentric and two telocentric elements and characterized by the presence of two short side-arms. Meanwhile, all trivalents are in a cis configuration. The study of G-banding also demonstrates that the No. 1 autosome polymorphism is caused by Robertsonian translocation. Robertsonian fission is the main reason of the polymorphism of chromosome No. 1 and of variation of chromosome number in M. mandarinus.

Animals↗
PubMed2000

[Image and quantity analysis of blood-gas in rabbit's artery and Na(+)-K(+)-ATPase in their lungs during PE-SWD treated by HFJV].

This study was made to gain an insight into the mechanism of high-frequency jet ventilation(HFJV) treatment for the pulmonary edema after seawater drowning(PE-SWD). PaO2, PaCO2 and oxygen saturation (SaO2) of the rabbit and Na(+)-K(+)-ATPase in the rabbit's lungs in three groups--PE-SWD group(PE-SWD-G), HFJV group (HFJV-G) and control group(CG), were measured and analysed by the blood-gas analyser and computer image system. The results showed that, after 100 minutes' HFJV, the PaO2, SaO2 and the activity of Na(+)-K(+)-ATPase in the lung capillary endothelial cells in HFJV-G were significantly higher than those in PE-SWD-G(P < 0.01 or P < 0.05). Three parameters of Na(+)-K(+)-TAPase(G1, D1 and D2) in HFJV-G almost returned to their values in CG. The authors suggest that the increase of PaO2 and SaO2 in the rabbit's artery blood in HFJV-G is closely related to the rehabilitation of Na(+)-K(+)-ATPase activity in the lungs after HFJV. The mechanism of successful HFJV treatment for PE-SWD is that HFJV can better correct hypoxemia and improve the rehabilitation of Na(+)-K(+)-ATPase activity in the rabbit's lungs.

Animals↗
PubMed2000

[Study on the mechanism of pulmonary edema after seawater drowning in rabbit].

To study the mechanism of pulmonary edema after seawater drowning (PE-SWD), the indexes of blood-gas and acid-base in rabbits artery blood were measured by the blood-gas analyser. The activity of Na(+)-K(+)-ATPase, cytochrome oxidase(CYTO) and alkaline phospharase(ALP) in the lungs were measured and analysed by computer image system. C-fos mRNA and Fos protein in the lungs were respectively determined by situ hybrioization and immunohisto chemical techniques. The distribution of phospholipid and Ca2+ of rabbits lungs was quantitatively analysed by ultrastructural location method. The results showed that, five parameters of PaO2, oxygen saturation(SaO2), pH, actual bicarbonite(AB) and base excess(BE) and the activity of Na(+)-K(+)-ATPase and CYTO decreased remarkably in PE-SWD. Both c-fos mRNA and Fos protein expression in pulmonary epithelial cells in PE-SWD were significantly elevated compared with the normal controls(P < 0.01). The phospholipids products in the pulmonary alveolar type II epithelial cells were decreased, however, the Ca2+ precipitate pellets inside the lung capillary endothelial cells and the pulmonary alveolar type I and II epithelial cells increased obviously. The arthors suggest that the injuny action of the seawater, hypoxia and metabolic acidosis may be the mian three mechanisms of the pulmonary edema induced seawater drowning. The lowering activity of Na(+)-K(+)-ATPase and CYTO in the lungs and calcium overload in the cells are not only evil consequence resulted from above three factors, but also the importent causes leading to the worse of PE-SWD. The transmiting line of Ca(2+)-fos may be also a key link to bring about the worse of PE-SWD.

Acidosis↗
PubMed2000

[Chemical study of Alpinia officinarum].

Seven compounds were isolated from Alinia officinarum Hance and were identified as beta-sitoterol, 1,7-diphenyl-5-ol-3-heptone, 1-phenyl-7-(3'-methoxyl-4'-hydroxyl) phenyl-5-ol-3-heptone, glandin, kaempferol-4'-methylether and 3,4-dihydroxylbenzoic acid by IR, 1HNMR, 13CNMR, FAB-MS and EA. Among these compounds, 3,4-dihydroxylbenzoic acid was the first time obtained from Alpinia officinarum Hance. Furthermore, 1-phenyl-7-(3'-methoxyl-4'-hydroxyl) phenyl-5-ol-3-heptone and a new compound 1,7-diphenyl-3,5-heptandiol-phenyl-7-(3'-methoxyl-4'-hydroxyl) phenyl-3,5-heptaxdiol were obtained from 1,7-diphenyl-5-ol-3-heptone and 1-phenyl-7-(3'-methoxyl-4'-hydroxyl) phenyl-5-ol-3-heptone via chemical reductions.

Alpinia↗
PubMed2000

Growth inhibition, induction of apoptosis by green tea constituent (-)-epigallocatechin-3-gallate in cultured rabbit lens epithelial cells.

PURPOSE: To evaluate effect of green tea extract (-)-Epigallocatechin-3-gallate (EGCG) in cultured rabbit lens epithelial cells in order to pave a new way to postcapsular opacity (PCO) prevention. METHODS: Cell survival rate was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) coloimetric assay. Cell apoptosis was detected by electron microscopy, Hochest 33258 stain and flow cytometer. DNA fragment was detected using agarose gel electrophoresis. RESULT: Proliferation of the cultured rabbit lens epithelia cells was inhibited by EGCG in a dose and time dependent manner. Morphologic study showed that the cells became shrunk, round shaped with their nuclei condensed and broken. Apoptotic bodies were also seen under electron microscope and in Hochest 33258 stain assay 24 hours after EGCG was added to the medium. DNA ladders were shown in agarose gel electrophoresis. In flow cytometry assay, apoptosis peak was also evident. CONCLUSION: Green Tea Constituent(-)-Epigallocatechin-3-gallate could inhibit cultured rabbit lens epithelial cells proliferation by inducing their apoptosis in the concentration used by us, which indicates that it is possible to prevent PCO by using herb extract.

Animals↗
PubMed2000

Retrograde labeling of adult rat retinal ganglion cells with the flurogold.

PURPOSE: To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely. METHODS: FG was injected to the superior colliculi(SC) and dorsal lateral geniculate nuclei (dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time. RESULTS: FG-labelled RGC were observed in the retina as early as 3 days after application of FG. The labelled cells gradually increased in density, reached 95% of the maximal number on days 7 and the maximal number on days 30. The density of labelled cells was higher in the posterior pole than in the peripheral area. The fluorescence intensity in labelled cells maintained up to 60 days. CONCLUSION: The FG retrograde labeling method is reliable and effective for quantity of RGC.

Animals↗
PubMed2000

The study on the expression of keratin proteins in pterygial epithelium.

PURPOSE: To evaluate the expression patterns of several keratin proteins in pterygial epithelium. METHODS: The proteins of K8, K10, K14, K16 and AE3 in the epithelium of 8 pterygia and 4 normal conjunctiva were detected using immunofluorescent staining. RESULTS: In pterygial epithelium, the staining patterns of 5 keratin proteins were different with normal conjunctiva. No staining of K8, K10 and K16 was detected in normal conjunctival epithelium, but in pterygial epithelium, K8 and K16 were present in full thickness and K10 was present in superficial cells. In normal conjunctiva, only base layer of epithelium showed positive staining with antibody of K14 and AE3 proteins, but they were present in the full thickness in pterygial epithelium and the antibody of AE3 protein stained the superficial cells heavily comparing with base cells. CONCLUSION: The abnormal expression of keratin proteins (K8, K10, K14, K16 and AE3) in pterygia indicates that the epithelial cells in pterygia are in the state of hyperproliferation and keratinization, which may be the cause of the abnormal tear function in patients with pterygia.

Adult↗
PubMed2000

[Protective effects of brain-derived neurotrophic factor on injured retinal ganglion cells of rats].

PURPOSE: To investigate in vivo the survival of retinal ganglion cells(RGC) after optic nerve crush with intraocular injection of Brain-derived neurotrophic factor (BDNF). METHODS: Sprague-Dawly(SD) rats were divided into normal control, crush control, medium treatment and BDNF treatment group, and every group had 20 eyes. RGC of adult rats were labeled with fluorogold. Seven days later, the optic nerve was intraorbitally crushed and BDNF was injected into the vitreous. Five, 7, 14, 21 and 28 days after crush, the numbers of RGC were counted. RESULTS: The densities of RGC began to decrease 7 days after injury, the number of RGC was 70.2% and 40.5% of normal controls on days 14 and 28, respectively. In the group with BDNF injection, RGC densities decreased on days 7, but RGC densities were much higher than that of controls on 7, 14, 21, and 28 days after injury (P < 0.01). CONCLUSION: BDNF administered intraocularly at the time of crush can protect RGC from injury and cell death.

Animals↗
PubMed2000

[Clinical investigation of 0.3% levofloxacin eyedrops on the treatment of cases with acute bacterial conjunctivitis and bacterial keratitis].

PURPOSE: To investigate the effects of 0.3% levofloxacin eyedrops on the treatment of acute bacterial conjunctivitis and bacterial keratitis. METHODS: The patients were randomly divided into treated group and control group. They were given 0.3% levofloxacin and 0.3% ofloxacin eyedrops respectively. RESULTS: From April to December in 1999, 132 cases were enrolled in the study. It showed that there was no significant difference between two drops in the cure and effective rates, but the mean cure day of keratitis in levofloxacin group was significantly shorter than that in ofloxacin group. No serious side effects occurred. CONCLUSION: Levofloxacin eyedrops was effective and safe antibiotics in treating bacterial conjunctivitis and keratitis.

Adolescent↗
PubMed2000

[Establishment of the animal model of triple semicircular canal occlusion].

OBJECTIVE: To establish the animal model of triple semicircular canal occlusion(TCO) in guinea pigs. METHODS: TCO was performed on 20 guinea pigs. Electronystagmography, auditory brainstem responses (ABR) and distortion product otoacoustic emissions(DPOAE) were recorded pre- and post-operatively. The non-operated ear was used as control. RESULTS: There was spontaneous nystagmus towards non-operated side on the 1st postoperative day and no nystagmus to stimuli of sinusoidal angular acceleration in operated side. On the 30th postoperative day, left and right nystagmus returned symmetrical. Pre-operation, ice-water stimulation induced normal symmetric nystagmus in both sides. On the 30th postoperative day, ice-water stimulation only induced normal nystagmus in non-operated ear and failed in operated one. ABR thresholds increased approximately 10 dB post-operation. There were no significant changes of the amplitudes of DPOAE before and after surgery. Histologic examination revealed complete occlusion in the three semicircular canals with newly formed bone and connective tissue. CONCLUSION: This study showed that the animal model of TCO was successfully established. These findings suggests that TCO might be a safe and simple procedure for the treatment of intractable peripheral vertigo.

Animals↗
PubMed2000

[Intracytoplasmic injection with sperm from ejaculation, epididymis and testis in treating different male infertility with oligo-asthenozoospermia or azoospermia ].

OBJECTIVE: To retrospectively study 400 intracytoplasmic sperm injection (ICSI) cycles by using three different sources of sperm. METHOD: Different male infertility with oligo-asthenozoospermia or azoospermia was treated by ICSI using sperm from ejaculation, epididymis and testis. RESULTS: In the ejaculation group (n = 277), the fertilization rate was 69.6% and the clinical pregnancy rate 28.9%. In the 104 cycles using epididymal sperm, the fertilization and clinical pregnancy rate was 65.9% and 37.5% respectively. And the fertilization and clinical pregnancy of testis sperm (n = 19) was 65.7% and 21.1%. The difference of fertilization and clinical pregnancy rate among the three groups were not significant. CONCLUSIONS: Male infertility of different causes can be treated by ICSI. The outcome has nothing to do with the common parameter of semen except that the sperm motility is 0, but the effectiveness of ICSI should be studied by long-term observation.

Adult↗
PubMed2000

[Assay and L1 gene sequence analysis of human papillomavirus type 6 and 11 in condylomata acuminata].

OBJECTIVE: To determinate the prevalence of HPV type 6, 11 in condylomata acuminata, and analyze the sequence of L1 gene and its deduced L1 protein. METHODS: PCR was used to amplify DNA sequences between E6 and E7 of HPV type 6 and 11. The PCR products were identified by the fragment length cleaved with restriction enzyme RsaI. L1 genes were amplified with high fidelity Taq, and cloned DNA sequences were detected by the dideoxynucleotide method. RESULTS: In 34 examples of condylomata acuminata, HPV11 was found in 25 examples (73.5%), HPV6 in 15(44.1%), including HPV6 + HPV11 in 6(17.6%). In comparison with the prototypes there were 7-8 point mutations in HPV11 L1 gene and 3 in HPV6L1 gene. L1 encoded protein changes showed up only in 1-3 amino acids in the former cases. CONCLUSION: Most of patients tested with condylomata acuminata are mainly infected by HPV11, the rest of them by HPV6 or by co-infection of two mixex types. Sequence analysis of L1 genes indicated that mutations were found in both HPV6 and 11, whereas deduced amino acid mutations in L1 protein were limited in HPV11 only.

Adult↗