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Biomedical subjects

Y Shen

Publications and source records attributed to Y Shen.

At least 307 records · Page 17Linked to original sources
PubMed1998

Expression of calmodulin-binding domain of neuronal nitric synthase and its binding activity to calmodulin.

To facilitate the study of associations of nNOS functions with its calmodulin (CaM) binding domain and to prepare nNOS specific inhibiting peptides from phage peptide library, we have amplified the coding gene of nNOS CaM-binding domain (nNOS 2544-2988 bp) and expressed it in E.coli. The recombinant product in the size of 22 kDa was purified (over 90% in pure) by His.Tag-Sepharose column and its obvious CaM-binding activity was detected with CaM overlay assay. Since it possesses the sequence specificity and effective calmodulin-binding activity, the protein was considered an ideal target for screening nNOS specific peptides from peptide library and also an antigen for marking nNOS antibody.

Binding Sites↗
PubMed1998

[Scavenging effect of total flavonoids of lycium barbarum L on active oxygen radicals and inhibitory effects on heat output from L1210 cells].

The scavenging effects of total flavonoids of Lycium barbarum L. (TFL) were studied by using ESR-spin trapping technique and the inhibitory effects on heat output of both polymorphonuclear leukocyte(PMN) respiration burst and L1210 cells were measured by using microcalorimetric technique. TFL (0-217 mg/L) could scavenge O2-. in xanthine/xanthine oxidase (Xan/XO)system, with scavenging rate of 0-51%. TFL(7.5-200 mg/L)could scavenge OH. produced in Fenton reaction and the scavenging rate is between 20% to 72%. Those effects were concentration-dependent. Furthermore, TFL(0.56 g/L)could completely inhibit the heat output from PMA-stimulated PMN and TFL(1.0-5.0 g/L)could inhibit the heat output from L1210 cells.

Animals↗
PubMed1998

[Investigation of hepatitis B virus infection in blood donors].

To investigate the status of HBV-M and HBV DNA in blood donors, 583 serum samples were detected by ELISA technique and polymerase chain reaction. The results were that hepatitis B virus marker(HBV-M) positive rate was 55.9%(326/583), HBV DNA 9.78%(57/583). The data indicate that there is high incidence of HBV infection in blood donors. The donors should be strictly tested for HBV in the future.

Adolescent↗
PubMed1998

[Idiopathic interstitial nephritis induced acute renal failure: clinical and pathological analysis].

OBJECTIVE: To understand idiopathic interstitial nephritis (IIN) and its relationship with acute renal failure as well as its clinical and pathological characteristics for avoiding misdiagnosis and missing diagnosis. METHOD: A detail clinical and pathological analysis was performed on 7 patients with idiopathic interstitial nephritis. RESULTS: The major manifestations were acute non-oliguric renal insufficiency combined with mild proteinuria (< 2 g/d), microscopic hematuria and obvious disorder of renal tubular function (for example, glycosuria). Three patients had high gamma-globulinemia and 2 were associated with uveitis. Renal biopsy showed typical tubulointerstial nephritis but glomeruli, and the renal vasculature was almost normal. All patients were treated with prednison. Renal function recovered in 5 patients. CONCLUSION: When a patient has renal insufficiency especially non-oliguric renal failure with disorder of tubular function without definite causes, IIN should be considered. The diagnosis and treatment should be done immediately.

Acute Kidney Injury↗
PubMed1998

[Choices of anesthesia in operations of extraction of foreign body in esophagus].

In order to probe the anesthetic methods of extracting foreign body in esophagus and improve operative effect, potentiated surface anesthesia and intratracheal intubation anesthesia were applied in operations to 72 cases of foreign bodies in esophagus, and comparative observations were done to these cases. All the cases had their foreign bodies extracted smoothly and no serious complications occurred. We consider that each anesthetic method has its advantage. The former is suitable for the adolescents and adults, the latter is suitable for the young children who have foreign bodies in esophagus and difficult breathing.

Adolescent↗
PubMed1998

[Head trauma and brain auditory evoked potentials].

The study investigated brain auditory evoked potentials (BAEP) in patients complaining auditory disturbances after head trauma. The results showed that the incidence of hearing loses was 57.5% and the rate of abnormality of BAEP is 33.75%. The types of the abnormalities of BAEP varied and were related with the position and severity of the head trauma. The types of the abnormalities manifested as loses of I-II waves, prolongation of V latency and I-V interlatency.

Adolescent↗
PubMed1998

[Experimental studies on anti-inflammatory, antipyretic and diuretic effects of several species of tongcao and xiao-tongcao].

OBJECTIVE: To observe and compare the anti-inflammatory, antipyretic and diuretic effects of three kinds of Tongcao(Tongtuomu, Panyezhangyeshu and Luosan) and seven kinds of Xiao-tongcao(Ximashanjinjiehua, Xinanxiuqiu1. 2., Ditanghua, Suixuezhangcai, Qingjiaye and Zhongguo jinjiehua). METHOD: Decoctions prepared from the above kinds of Tongcao and Xiao-tongcao crude drugs were given to rats at dosages of 8 g/kg and 4 g/kg by ig. Pharmacological actions were observed by means of carrageenan-induced swelling paws, fever models induced by beer-yeast or carrageenan and metabolic cage method in rats. RESULT: All the experimental decoctions could inhibit carrageenan-induced swelling of rat paws in different degrees and exerted anti-pyretic effect on rat fever models induced by beer-yeast or carrageenan. Three kinds of Xiaotongcao(Ximashanjingjiehua, Xinanxiuqui2., Zhongguojinjiehua) had obvious diuretic effect on rats. CONCLUSION: Decoctions of different species of Tongcao and Xiao-tongcao all have anti-inflammatory, antipyretic and diuretic effects, thus providing some pharmacologic basis for the efficacy assay, clinical application, species collation and quality study of Tongcao and Xiao-tongcao.

Analgesics, Non-Narcotic↗
PubMed1998

[Application of capillary non-gel sieving electrophoresis to the analysis of short tandem repeat in phenylalanine hydroxylase gene and gene diagnosis of phenylketonuria].

OBJECTIVE: To establish a sensitive, accurate and reliable method for analysis of short tandem repeat (STR) markers for gene diagnosis, capillary electrophoresis (CE) was used for analysis of a polymorphic tetranucleotide (TCTA)n in intron 3 of the phenylalanine hydroxylase (PAH) gene. METHODS: Capillary non-gel sieving electrophoresis (CNGSE) system was used to analyze PCR products of PAH STR among 61 normal Chinese individuals and 6 phenylketonuria (PKU) families. RESULTS: The PCR fragments that differ 4 bp from each other were well separated by CNGSE. Ten alleles were identified, with a continuous distribution from 224 bp to 260 bp. The largest allele (260 bp) was first detected in Chinese population. The alleles frequencies were calculated and PIC is 0.738. The genotypes of PAH STR of total 80 Chinese people were also analyzed and the heterozygosity is 75%. We used this procedure to PAH gene linkage analysis in 6 PKU families, in which pathogenic gene could be affirmed in 3 families, including one case of prenatal diagnosis. CONCLUSIONS: In comparison with denaturing polyacrylamide gel electrophoresis, CE is an accurate, rapid, automatic and with high resolution analytical tool. CE in combination with PCR is a hopeful technique and might be widely used for gene diagnosis of genetic diseases in the future.

Alleles↗
PubMed1998

[The effects of epinephrine and adrenergic antagonists on adenosine 3', 5'-monophosphate level of bovine trabecular cells in vitro].

OBJECTIVE: To determine the effects of epinephrine (EPI) and adrenergic antagonists on adenosine 3', 5'-monophosphate (cAMP) level of bovine trabecular cells (BTC) in vitro. METHOD: (3)H-cAMP was used in protein binding assay for measuring the intracellular level of cAMP. RESULTS: (1) 10(-5) mol/L EPI induced a fold increase of cAMP in cultured BTC in vitro; (2) Timilol and ICI 118, 551 blocked efficiently the effect of EPI at a lower concentration (10(-6) mol/L). (3) Bisoprolol did not efficiently block the effect of EPI unless at high concentrations (>or= 10(-5) mol/L). CONCLUSION: The effects of EPI increasing outflow facility may be associated with its increase of cAMP in trabecular cells; BTC contains beta-adrenergic receptors, and beta(2)-adrenergic receptors are dominant.

Adrenergic beta-Antagonists↗
PubMed1998

[Synthesis and biological activity of 1-(4-acylamino)benzyl-1,2,3,4-tetrahydroisoquinolines].

For searching more effective antiarrhythmic agents, on the basis of integration of the structural feature of certain potassium channel blockers available, various acylamino groups were introduced to the position 4 of the benzyl ring of this series of compounds. Thus, eight 1-(4-acylamino)benzyl-1,2,3,4-tetrahydroisoquinolines were designed and synthesized, which had not been reported in the literatures. Compounds V1, V2 and V6 at concentration 10(-6) mol.L-1 depressed rat aortia contraction induced by high KCl (80 mmol.L-1). The effect was similar to that of tetrandrine. Compound V6 showed potent antiarrhythmic activity at the dosage of 1 mg.kg-1.

Aminoquinolines↗
PubMed1998

[Establishment of Hymenolepis diminuta-animal model and morphology of cysticercoid].

AIM: To observe the morphological changes in the process of the development of Hymenolepis diminuta. METHODS: The life cycle of Hymenolepis diminuta was established between Rattus domesticus albus and Triboliun castaneum. The morphology of cysticercoid were observed microscopically, and the ultrastructure of the body surface of cysticercoid were observed by scanning electron microscopy. RESULTS: Three phases including the mature stage, the blister stage and the protective outer membrane-forming stage during the growing course of cysticercoid were observed microscopically. Under scanning electron microscope, lots of sieve-like micropores on the surface of mature cysticercoid were seen in the second week after infection. The blister phase was found in the third week and the outer membrane measuring about 45 microns in thickness were found surrounding the cysticercoid and vesicular surface, forming a smooth cyst wall in the fourth week. CONCLUSION: The life cycle of Hymenolepis diminuta has been established in the animal-model. The finding of the three phases during the growing course of cysticercoid is reported for the first time.

Animals↗
PubMed1998

[Researches on immunogenicity identification of recombinant Sj22.6(rSj22.6) kDa antigen gene of schistosoma japonicum].

AIM: To identify the immunogenicity and the potentiality of rSj22.6 as a candidate vaccine antigen for schistosomiasis japonica. METHODS: rSj22.6 was tested by Western blot with specific antibodies to identify its immunogenicity. The rSj22.6 protein was isolated and purified by SDS-PAGE and injected twice into rabbits to raise antirSj22.6 serum that was tested by Western blot to recognize the native protein of adult S. japonicum and SEA. C57 mice were immunized with rSj22.6 and challenged with S. japonicum cercariae to identify the protective immunity raised by rSj22.6. RESULTS: rSj22.6 could be recognized by specific antibodies and could stimulate the rabbits to produce high level of anti-rSj22.6 antibodies. Anti-rSj22.6 serum could recognize an adult native protein with the same molecular weight as rSj22.6. The preliminary immune-challenge test resulted in significant reduction in adult worm burden. CONCLUSION: rSj22.6 possesses immunogenicity in stimulating rabbits to produce high level of specific antibody and has protective role as a candidate vaccine antigen against S. japonicum infection.

Animals↗
PubMed1998

[Researches on the nucleotide sequencing of the recombinant Sj 22.6 kDa antigen gene of Schistosoma japonicum].

AIM: To sequence the cloned gene in pGSj24 and to identify the encoded protein. METHODS: The cloned gene in pGSj24 was digested from the recombinant plasmid by EcoRI, ligated into the M13mp19 vector and sequenced by automatic sequencer. The sequence was analyzed by Goldkey DNA and Protein Analytical Program and DNASIS Program. RESULTS: The pGSj24 cloned gene was demonstrated to be 840 bp containing one opened reading frame (ORF) with an initiation codon ATG at position 23 nt and a termination codon TAA at position 596 nt, encoding a protein with a molecular weight of 22.6 kDa. At the upstream and downstream of the ORF there were termination codons, so the encoded protein was unable to be larger. However, there was a termination codon TAA at position 11 nt, suggesting why the 22.6 kDa protein expressed separately. The nucleotide sequence of the pGSj24 cloned gene shared 95% identity with that of the corresponding part of S. japonicum 22.6 kDa antigen gene, and 99.7% identity in the encoding part. The deduced amino acid sequence analysis showed a sequence motif known as EF-Hand calcium binding domain, several endoplasmic reticulum targeting sequences and microbodies C-terminal targeting signals. The possible antigen determinants were predicted within the amino acid fragments of 29-32aa, 63-68aa and 87-101aa. CONCLUSIONS: The cloned gene in pGSj24 is the gene that encodes Sj22.6 kDa antigen.

Amino Acid Sequence↗
PubMed1998

[Preliminary studies on pharmacological actions of tongca and xiao-tongcao polysaccharides].

OBJECTIVE: To study and compare the immunologic function and antioxidative effect of Tongcao(Tongtuomu) and Xiao-Tongcao(Ximashanjingjiehua, Xinanxiuqiu, Ditanghua) polysaccharides. METHOD: Mice were abdominally administrated with four kinds of polysaccharides at dosages of 80 mg/kg and 40 mg/kg for 7-10 days. RESULT: Four kinds of polysaccharides could increase the serum-lysozyme activity, phagocytic function of MPS and the serum hemolysin-antibody level in mice, inhibit the delayed hypersensitivity induced by DNCB in mice and raise the serum-catalase activity in mice. CONCLUSION: Four kinds of Tongcao or Xiao-Tongcao polysaccharides have immunoregulative function and antioxidative effect. The results could enrich the contents of "A Study on Species-Sorting and Quality of Tongcao-Xiao-Tongcao Crude Drugs".

Adjuvants, Immunologic↗
PubMed1998

[The influences of TBP on the partially saponified DMHPA-heptane systems and the extracted organic phases containing rare earth].

The aggregation states of partially saponified [di-(1-methylheptyl) phosphoric acid] (DMHPA)-tributyl phosphate (TBP) heptane (C7H16) and the extracted organic phases containing rare earth were studied. The result demonstrates that TBP can widen the range of the microemulsion formation in DMHPA-C7H16-NaOH-H2O systems. It also influence the states of the extracted organic phases of DMHPA-RE (III) and the behavior of water clearly. The gel could be formed in DMHPA-TBP-RE (III) systems under proper conditions. FT-IR spectra analysis shows that both DMHPA and TBP may coordinate with RE3+ and the hydrogen bonds of TBP with DMHPA and H2O contribute to the three dimensional network structure of the gels.

English Abstract↗
PubMed1998

[Indirect determination of trace amount of oxalic acid radical by the I2-CCl4 extraction spectrophotometry].

The article studies that in dilute H2SO4 dielectric substance IO3(-) reacts with C2O4(2-) to release certain amount of iodine under certain reaction condition: 2IO3(-) + 5C2O4(2-) + 12H+ = I2 + 10CO2 increasing + 6H2O therefore the method of indirect determination with I2-CCl4 extraction spectrophotometry is established. The reaction temperature is controlled in 90 degrees C; the reaction time 3 minutes; the reaction acidity pH1.0-2.0. The common ion basically does not affect the determination. The lowest detection limit of C2O4(2-) is 0.08 microg x mL(-1). After comparing the method of the recovery experiment with that of other determination, a satisfactory result is aquired and the recovery is between 96-98%.

Calibration↗
PubMed1998

Philadelphia chromosome-positive myeloid cells in the peripheral blood of chronic myelogenous leukemia patients: comparison with the frequency detected in cycling cells of the bone marrow.

Monitoring the frequency of the Philadelphia (Ph) chromosome in chronic myelogenous leukemia (CML) is important in determining the effectiveness of treatment for patients during therapy. This can be done with high resolution by subjecting short-term bone marrow cultures (48 h) to 24 h of mitotic arrest before harvest and detecting Ph-positive (Ph+) metaphases by fluorescence in situ hybridization (FISH) in a procedure termed hypermetaphase FISH or HMF. Here, we compared procedures for detecting Ph+ interphase cells (interphase FISH or I-FISH) in peripheral blood polymorphonucleocytes (PMNs) with HMF results on the bone marrow of the same 26 CML patients in different stages of remission. The probes for I-FISH in these experiments were relatively large (200-300 kb) and sufficiently resolved in PMNs so that 97.5% of the cells were scorable. The correlation between the frequencies of Ph+ cells from the two different cell sources was excellent (r = 0.983, P < 0.0001); however, there was a consistently higher level of Ph+ cells observed in the cycling marrow cells than in the peripheral blood PMNs. This was discussed in terms of current theories of apoptosis in CML cells. The large number of PMNs analyzable by I-FISH (approximately 500/patient in this study) provided sufficiently narrow 99% confidence intervals to suggest the procedure as an effective and efficient method for monitoring the frequency of Ph+ cells in CML patients undergoing therapy. However, for detection and quantification of minimal residual disease, HMF is preferable to I-FISH because of the much lower frequency of false-positive readings with the former procedure.

Adult↗